


Working Out the Kinks (Kinktober 2018)

by popatochisp



Category: Undertale (Video Game)
Genre: Affection, Alternate Universe - Horrortale (Undertale), Alternate Universe - Swapfell (Undertale), Alternate Universe - Underfell (Undertale), Alternate Universe - Underswap (Undertale), Bad Puns, Body Worship, Bodyswap, Bondage, Boot Worship, Brainwashing, Breeding, Chocolate Syrup, Choose Your Own Adventure, Collars, Come Eating, Communication, Consensual Non-Consent, Consensual Somnophilia, Costumes, Creampie, Cunnilingus, Daddy Kink, Deepthroating, Derogatory Language, Dom/sub Undertones, Established Relationship, Exhibitionism, F/M, Feeding Kink, Fisting, Food Kink, Foot Fetish, Fucking Machines, Gags, Gender-Neutral Pronouns, Hand Jobs, Heavy Petting, Horrortale Papyrus (Undertale), Horrortale Sans (Undertale), Humiliation, Humor, Hurt/Comfort, Intercrural Sex, Jealousy, Kinktober 2018, Laughter During Sex, Light Petting, Light Sadism, Lingerie, Loss of Identity, M/M, Mating Cycles/In Heat, Medical Kink, Military Ranks, Mind Control, Mirror Sex, Multi, Obedience, One-Sided Nudity, Oral Sex, Orgasm Delay/Denial, Overstimulation, Pegging, Porn with Feelings, Possessive Behavior, Public Sex, Reader-Insert, Roleplay, Rough Sex, Safeword Use, Self-Esteem Issues, Semi-Public Sex, Size Difference, Soulmates, Sounding, Stuffing, Swapfell Papyrus (Undertale), Swapfell Sans (Undertale), Telepathic Bond, Teratophilia, Trust Kink, Underfell Papyrus (Undertale), Underfell Sans (Undertale), Underswap Papyrus (Undertale), Underswap Sans (Undertale), Uniform Kink, Vaginal Fingering, Vibrators, Voice Kink, Voyeurism, Wall Sex, Wet & Messy, bone kink, distracted sex, hot-dogging, probably only applicable in this fandom
Language: English
Status: Completed
Published: 2018-10-08
Updated: 2018-10-30
Packaged: 2019-07-28 00:08:14
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 32
Words: 26,358
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16230119
Author URL: https://archiveofourown.org/users/popatochisp/pseuds/popatochisp
Summary: Want to sex up a skeleton? Sure you do! Come on in and let's get boning!-Prompt fills for Kinktober 2018, mostly used as character/relationship exploration for various AUs (UT classic, US, UF, SF, and HT). If you like your kink with a side of feels, you're in the right place!





	1. Perfect (UF!Papyrus/Reader, Deep-Throating)

**Notes for the Chapter:**

>  **Day 1:** _Deep-Throating_ | ~~Inflation~~ | ~~Face-Sitting~~ | ~~Masks~~
> 
>  **Pairing:** UF!Papyrus/Reader
> 
>  **Additional Kinks:** D/s undertones, brat-taming, hair-pulling

The sight of you crawling towards him on hands and knees is probably his _favorite_ thing in the world.

Papyrus had never thought much of humans—they were always an obstacle, The Enemy, something to be fought, avoided, despised.

…But that all seems _so_ long ago now, back before he’d ever actually met a human for himself.

He’s met a human by now; several, in fact. And they’re perhaps not… _quite_ so intolerable as he’d thought. As a species, though, they’re hardly enough to impress the Great and Terrible Papyrus!

Except for you, naturally.

You’re a stunning, _shining_ example of humanity, with your sparkling wit and brilliant mind and the curvaceously attractive body to match. You’re perfect, probably the most perfect human to ever exist on this whole miserable planet.

Of course you are: you’re _his._

You reach him and run your hands along his spread femurs slowly, sensually, but Papyrus can see the desire in your face to go faster, to have more.

It makes him grin.

“GOOD HUMAN,” he purrs, running his claws through your hair. The way the sharp points skim so, so lightly against your scalp makes you shiver. “YOU’VE BEEN PATIENT. TAKE YOUR TREAT.”

You undo his belt and free his cock with your deft little fingers in no time at all. The red glow of his magic catches in your eyes and when you look up at him, coy yet hungry, it truly makes you look like a human possessed.

Papyrus couldn’t be any more _pleased._

He’s quick to revise the thought when you touch him with your wet tongue, your soft lips, and then your hot, _hot_ mouth.

He should’ve known by now that you were an expert at pleasing him. You could _always_ find a way to do it _more._

Papyrus strokes you while you work between his legs, bobbing up and down on his cock like it was your job and making the most sinfully delicious noises while you did it.

“SUCH A GOOD PET,” Papyrus coos at you, his raspy voice going husky and low. Even _he_ can’t be unaffected when you swirl your tongue around his head _just_ so and moan with your mouth full of him. “YOU KNOW WHAT YOU’RE GOOD FOR. YOU KNOW YOUR PLACE…”

If he’d been paying more attention, he may have noticed the sharp look in your eyes at his words, just as shrewd and calculating as he’d ever been.

But he’s _not_ paying attention. Papyrus is _very_ distracted, you’re making sure of that.

It’s no wonder, then, that he’s taken totally by surprise when you suddenly grip his pelvis and surge forward.

In one smooth motion, you take his entire length deep into your throat and _swallow._

“GGHK!”

Papyrus fists his claws in your hair and yanks, all but dragging you off of him. You cough a little, but you’re fine.

Better than fine.

You can see just how much you got to him, the vibrant glow across his cheekbones lighting up the room even more than his erection, still glistening with your saliva.

He’s panting, flustered, _glaring_ at you, positively affronted.

“YOU NAUGHTY LITTLE MINX,” he snaps, “ACTING LIKE YOU’RE IN CONTROL!”

You smirk up at him, mischief in your gaze. “Aren’t I?” you ask.

Papyrus’ eye-sockets widen and then narrow.

_IS THAT HOW YOU WANT TO PLAY TONIGHT, PRECIOUS…?_

A smirk spreads slowly across his skull, matching yours. The sight of it sparks a thrill in your chest.

Papyrus moves his hand to the back of your neck and pulls you forward again. His cock rests against your cheek and you nuzzle it, looking as sweetly innocent as you _aren’t._

“I DON’T KNOW,” he says, his eager tone a promise. “LET’S FIND OUT, SHALL WE?”

Papyrus thinks he must be the happiest monster in the world: he’s chosen the most _perfect_ human in it to be his mate.

**Notes for the Chapter:**

> My Brain: Hey, you know what's a good idea? Kinktober, let's do that.
> 
> Me: Really? I've never done that before. And I'm already starting a week behind. And I have an ongoing fic that's like the exact tonal opposite of kinky that probably deserves more of my attention...
> 
> My Brain: Shhh, just come.
> 
> Me: ....nice.
> 
> My Brain: Nice.
> 
> -
> 
> Well... here's this, I guess.
> 
> Will I catch up to the current day of prompts? Probably not. Will I be posting a chapter of this every day until I do? DEFINITELY not. Will I, eventually, at some point, possibly months down the line do all 31 days of prompts?
> 
> HELL YEAH.
> 
> Thanks for reading and happy Kinktober, everybody! :)


	2. Subject (UT!Sans/Reader, Medical Play)

**Notes for the Chapter:**

>  **Day 2:** ~~Ass Worship~~ | ~~Begging~~ | _Medical play_ | ~~Watersports~~
> 
>  **Pairing:** UT!Sans/Reader
> 
>  **Additional Kinks:** Bondage, gags, d/s overtones, orgasm control/delay/denial

You don’t ask where Sans got the table.

You tend not to ask where Sans gets anything and it’s for the best: you never get a straight answer anyway, just a shrug and a wink on the heels of a cheesy pun, and you get plenty of that as it is.

It looks startlingly authentic in the sterile white room of Sans’ lab. The navy-blue leather padding and the silver stirrups shine a little under the fluorescent lighting like it’s brand new—maybe it is. 

You feel a bit like you’d just popped into some gynecologist’s office to take a look around, but of course that isn’t the case.

You’re the one wearing the lab coat here, with a naked skeleton on your table and a tape-recorder in your hand.

“Subject is compliant,” you state for the record. “Allowed restraints to be applied without resistance.”

Sans watches you from the table. It’s all he can do with his arms bound behind his back and legs strapped into the stirrups that are holding them apart.

You have a fantastic view.

You should probably describe it for posterity.

“Subject is a skeleton. Similar in structure to that of a human with only minor differences. Subject _should_ logically fall apart without joints to hold him together; cited ‘magic’ as the reason he doesn’t. Or he _did,_ when he had speaking privileges.”

“mmh!”

Sans’ grunt sounds protesting, even through the gag you’d wedged between his teeth.

Willing to give him the benefit of the doubt, you approach and lean down. “Is there something _you’d_ like to state for the record?”

He nods and you remove the gag.

“what can i say, doc? ya’ leave me _speechl_ —mphf!”

You re-secure the gag. For the recording, you note, “Subject’s inability to keep his mouth shut is what necessitated the revocation of speaking privileges in the first place.”

Sans could never resist the urge to be a class clown. Not even to fulfill one of his _own_ fantasies.

“The purpose of this session is to gain _knowledge_ ,” you say sternly, “ _not_ to make jokes.”

Sans shivers a little when you scold him like that. You make a mental note of it, a reminder to explore it more later.

You’re a little preoccupied just now.

“Subject’s magic is blue in color, manifested in the torso from ribs to pelvis.”

You reach out and lightly graze your fingers along his soft, cyan belly. He’s warm and you feel him twitch beneath your touch, instinctively jerking against his restraints with a metallic ‘clack.’

They hold strong.

He wasn’t going anywhere, couldn’t cover himself up, couldn’t say a single word unless you allowed it. However you wanted to touch him, whatever you wanted to do while he was exposed and immobile… he was going to have to lie there and take it.

Sans seemed to be realizing that, too.

“Subject is showing signs of arousal,” you loudly announce. You want to make sure the recorder picks up these very important observations even as you take Sans in hand. “Genitals are phallic currently, erect and responsive to stimulation.”

You feel Sans’ cock twitch in your grip even as his skull _lights up_ with a flustered shade of blue.

He’s _loving_ this and you have to admit… you’re starting to get a little partial to it, yourself.

You turn your head to the tray beside the table. It’s practically overflowing with instruments and toys—more things Sans procured from you-didn’t-care-where.

You make absolutely sure Sans sees you looking at it all, your eyes lingering on the dozens of possibilities he laid out for you.

“ _Extensive_ testing is needed,” you say, and Sans begins to noticeably sweat. “Replicable results are the cornerstone of any scientific experiment, _multiple_ trials are in order, of course.”

You lean in a little, smiling as you drag your thumb along the underside of Sans’ cock torturously slow. His low moan is muffled by the gag and you pay it no heed.

“Perhaps at the end of the session,” you propose kindly, “with cooperation, the subject _may_ be allowed to orgasm.”

Sans’ little white eye-lights blip into hearts for you.

You think you’ve made up your mind: this _is_ fun…

**Notes for the Chapter:**

> .........there's not enough subby skeleton porn. There should always be more.
> 
> Thanks for reading!


	3. Trust (UF!Sans/Reader, Sensory Deprivation)

**Notes for the Chapter:**

>  **Day 3:** _Sensory Deprivation_ | ~~Temperature Play~~ | ~~Edgeplay~~ | ~~Knife Play~~
> 
>  **Pairing:** UF!Sans/Reader
> 
>  **Additional Kinks:** Trust, one-sided nudity, slight(ly more than usual) teratophilia, light-to-heavy petting

Sans stared down at the blindfold in his hands like he had no idea what it was.

“…are ya’ sure?”

It was a great question, one that should _always_ be asked before trying something new, but you were getting a little tired of hearing it.

It was only the tenth time he’d asked you _tonight._

“Yes, Sans, I’m sure,” you promise. You try to keep your tone gentle, in spite of your exasperation. “It’s okay, you can put it on.”

His clawed thumbs run along the fabric. He’s being careful not to hold it too tight and shred it, but you can see him starting to sweat.

“……i just wanna make sure,” he says again. “‘cause we don’t gotta… i mean, what if—”

“Sans.”

His jaw clicks shut and he looks at you with wide eye-sockets when you cut him off. You know he’s been conditioned to respond to direct orders and you try not to feel bad as you take advantage of it.

“Put the blindfold on me,” you tell him firmly.

Sans does it, reaching for you and blacking out your vision with the knot he ties at the back of your head.

You can’t see a thing and you smile, speaking into the void, “There, was that so hard?”

“eheheheh…” His vaguely nervous laughter makes you smile. You knew that Sans had been hesitant to try this out from the moment you brought it up, but you’d insisted; you just _knew_ that he would love it if he tried and if he really didn’t, it was a very easy kind of play to stop at any time.

But you don’t think Sans will ask to stop.

You can feel him shifting around a little on the bed, and you guess that he’s probably fiddling with the hem of his t-shirt like he always does when he feels awkward, but you can’t be sure.

You can’t see him: you can’t be sure of _anything_ he’s doing or could be about to do.

That’s why you like this so much.

Sans is new to it, though, so you’re not surprised when he eventually asks, “…now what?”

You just grin at where you’re pretty sure he is. “Anything you want, baby.”

“ _anything_?” He sounds incredulous, but you don’t back down.

“Anything.”

“………lay down.”

You do, settling back against the sheets and pillows without protest. There’s just a moment of hesitation before Sans comes to lean over you and presses his teeth to your lips.

You’re not sure how it works, kissing someone without lips—Sans had certainly never explained beyond a shrugged, ‘magic’—but he’s a good kisser and you sigh happily against his mouth as he moves to be fully on top of you.

You can feel his clothed bones rubbing up against your bare skin in all the right places. You were lying there beneath a red-eyed monster with sharp claws and a mouthful of fangs in nothing but your underwear and a blindfold.

It sends a thrill straight through your entire body and you moan into Sans’ mouth.

It’s obvious when Sans starts to get more confident. His impossible tongue comes out to play with yours and his once-gentlemanly hands start to stray further south.

He loves your human body, he’s told you so a hundred times and he explores the familiar territory of your flesh with straightforward enjoyment; carefully stroking and rubbing along all his favorite dips and curves.

You can’t predict his hands, you can’t _see_ the way he’s moving, reduced to guesses and hopes about where he’s going to touch you next, and you’re usually wrong yet pleasantly surprised. You jump whenever his claws slide against you somewhere you weren’t expecting, but you have to giggle a little from the excitement of it.

You’re blind, exposed, at Sans’ _mercy_ , he could do absolutely anything he wanted to you and you’d never see him coming, literally.

But you were laughing because you liked it; because you knew that Sans would never hurt you.

You trusted him.

You think Sans is figuring that out, too, because he growls against your mouth and starts tugging off your underwear.

You help him where you can and then he’s grabbing you by the wrist, holding out your hand. You hear a click and lube drizzles over your fingers while you try to catch it.

“get’cherself ready,” Sans orders gruffly.

You don’t hesitate to obey.

As your hand slides down between your legs, pressing your slick fingers inside yourself, all you can hear is the shuffle of clothing and Sans’ heavy breathing.

You can _feel_ his stare on you, though, scorchingly intense.

You have a feeling that the blindfold is going to be getting a lot more use from now on.

**Notes for the Chapter:**

> Underfell Sans is a blackened marshmallow who gets turned on by emotional security in a relationship, ~~you can't~~ change my mind.


	4. Beautiful (UT!Papyrus/Reader, Mirror Sex)

**Notes for the Chapter:**

>  **Day 4:** ~~Spanking~~ | _Mirror Sex_ | ~~Spit-roasting~~ | ~~Dacryphilia (Crying)~~
> 
>  **Pairing:** UT!Papyrus/Reader
> 
>  **Additional Kinks:** Orgasm control/delay, begging, d/s undertones

You were losing your mind. You were actually going completely, totally insane.

No matter how much you wriggled and squirmed and _whined,_ you were stuck, utterly helpless against the most deliberate and _torturously_ slow pace in the entire world.

You were so _close_ …but you’d been close for what felt like hours now with no release in sight.

Your eyes scrunching shut, you threw your head back in frustration and groaned your lover’s name.

“Papyyyyyyyyrus…!”

“DON’T CLOSE YOUR EYES,” the grinning skull at your neck chided. “YOU’RE MISSING THE BEST PART!”

“I thought…the other bit was the best part,” you panted.

Papyrus tsk-ed at you, sounding amused. “SILLY HUMAN,” he said. “IT’S _ALL_ THE BEST PART!”

You opened your eyes again.

In front of you, you could see it all, literally. The mirror showed you how widely your legs were splayed, reflected by the strain you were starting to feel in your hips but you couldn’t close them, not with Papyrus’ gloved hands holding them open—and holding you _up._

You were forced to lean back against his broad chest, an arm braced around his shoulders just to keep from toppling forward and you’d never been in a position that left you so completely _open_ before. If it were anyone else, you think you’d be scared, waiting for your partner’s strength to give out and fall flat on your face…

But this is Papyrus: his strength _never_ gives out.

He’s more than proven that by now as he holds you completely steady with ease, fucking into you in long, smooth strokes that send pleasure sparking up your spine with every passing second.

“I wanna come,” you moan, turning so your lips brush against the bone of Papyrus’ skull. “Please, Papy, it’s so…! It’s too much, I wanna come, I wanna come, _please_!”

Papyrus doesn’t take pity on you. “YOU’RE NOT _WATCHING,_ ” he insists, sounding annoyed.

You whimper but turn back to the mirror. Papyrus grins and nuzzles at your chest.

“LOOK AT US,” he encourages, “LOOK HOW WELL WE FIT TOGETHER…”

You see it, the way your bodies are pressed so deeply, intimately close that they seem to have been made for each other, just like—

“PUZZLE PIECES, YES!”

Papyrus always did have a knack for reading your mind.

It just makes it all the more frustrating that he’s going so slowly, when he _has_ to know how close you are, how _badly_ you want it.

“YOU’RE SO BEAUTIFUL,” he coos at you, leaning forward to press his teeth to your cheek.

Even without eyes for you to follow, you can tell he’s still looking at the mirror.

Papyrus had never been shy about the self-love he preached and practiced, or about the love he had for you. It had been a surprise for you when he said he wanted to do this, but only at first. 

Upon even a moment of reflection, it was obvious to you why he’d want to be able to watch the two of you making love, and why he’s dragging it out so excruciatingly long.

……ha, _reflection._ You’d have to make sure you didn’t say _that_ out loud, or Papyrus would _never_ let you come.

You could feel the pressure building in you, spiraling higher and higher even as you watched Papyrus’ cock moving in and out of your body with attention almost as rapt as his.

“Papyrus,” you whined one last time, “ _please…_ ”

Papyrus sighed.

“OH, FINE,” he relented, finally, _finally_ speeding up, and you felt like you could actually cry from the relief.

“SHOW ME, THEN,” he all but ordered you. “SHOW ME HOW INCREDIBLE YOU LOOK WHEN YOU COME ON MY COCK!”

“Mmnh…!”

Your world exploded into sparks of color. Pleasure made your toes curl and your back arch, writhing against Papyrus even as he held you still through your orgasm.

When it finally faded and you flopped back against him, sweat-drenched and spent, he spoke again, sounding reverent.

“BEAUTIFUL…”

**Notes for the Chapter:**

> Oblivious naïve virgin Papyrus? Never heard of her...


	5. Sugar (HT!Sans/Reader, Feederism)

**Notes for the Chapter:**

>  **Day 5:** ~~Feet~~ | ~~Sadism/Masochism~~ | _Feederism_ | ~~Shotgunning~~
> 
>  **Pairing:** HT!Sans/Reader
> 
>  **Additional Kinks:** None

Sans thought he’d hit the jackpot when he’d snagged a baker for a mate.

Not just any old hobbyist, either, his human was a real _professional,_ cranking out cakes and pies and pastries that were picture-perfect every time and every bit as mouth-wateringly delicious as they looked.

Better than Muffet’s, even, and he could actually say so now that Muffet was gone along with half of the Underground, perished in either the Fallen Human’s rampage or the famine that followed.

After every awful, horrific thing that happened down there, getting to live up here on the surface with his brother, and with a cute human that regularly got up on tip-toes to kiss his cheek and pass him a slice of freshly cut cake, well… it felt like paradise.

And it was…mostly.

Sans just hadn’t expected his sweet little mate to be such a _freak._

He probably should’ve seen it coming, the hints had been there. His biggest clue should’ve been that Thanksgiving dinner—the best thing he’d ever heard of, humans were _hilariously_ indulgent—when he’d fully embraced the spirit of the holiday and then promptly passed out on the couch.

He’d woken up to find his mate watching him, eyes trained on the generous curve of his midsection. At the time, he’d just passed it off as human fascination: his shirt had ridden up a bit in his sleep and the slate-blue glow of his magic was clearly visible.

Sans didn’t do too much magic these days but humans were always so interested in that stuff, always wanting to see more, asking how it worked. He imagined that his human was probably the same way.

Except the look on their face wasn’t fascination. He should’ve known better, should’ve recognized it—it was a look he’d seen Underground every day.

_Hunger._

Sans was huffing now, the taste of sugar on his tongue and an aching pressure in his gut that couldn’t be ignored.

He rubbed at his rounded magic, tight as a drum beneath his phalanges. His overfilled belly was pressing up on his ribs and making it hard for him to take a solid breath, but still…

There you were, holding out _another_ piece of pie.

“fffuck me, ya’ gotta be kiddin’,” he panted. “s’no way…”

You just look at him with those big doe-eyes, that syrup-sweet smile.

“Come on, Sans,” you murmur, your voice dripping with affection. “It’s the last one. You can eat one more, can’t you?”

He looked at the plate and you watched him war with himself. You can’t help but admire him all over, from his candy-apple red eye-light to the muted blue of his big stuffed belly, as shiny as a pulled sugar ribbon and twice as pretty.

His voice is small when he finally speaks. “……one more…?”

Your grin widens and Sans shivers: it’s like watching a predator spot a limping rabbit, _eager_ to pounce.

“Just one more,” you promise, pushing the pie closer. “I _know_ you can do it, you’re _so_ good for me…”

“mmmm……yer crazy,” he grumbles.

But he takes the plate.

You sidle right up to him, a line of warmth against his side as he forces down another bite. Your fingers start to rub at his belly in attentive little circles that ease the pressure and make it easier for him to keep going.

Sans knows those fingers are going to go a lot lower as soon as he finishes the treat you baked for him. Making him eat like this _always_ gets you frisky; makes you want to get him as excited as you feel watching him stuff himself until all he can do is lie there and try to catch his breath.

“…hhrrf…” Sans struggles, but manages to swallow one more bite. He thinks he can actually _feel_ his magic stretching to accommodate it. “yer lucky i love ya’…”

You reach up and kiss him on the cheek. “I love you, too,” you tell him, all smiles and warmth and sweetness.

You were a freak alright, getting off on something like this…but maybe Sans was a freak, too.

By the time you slip your hand into his shorts, he’s already rock-hard and ready for you.

**Notes for the Chapter:**

> .....................I...really like this one, I think. Don't judge me, we're all sinners here.


	6. Needy (US!Papyrus/Reader, Daddy Kink)

**Notes for the Chapter:**

>  **Day 6:** _Daddy_ | ~~Corset~~ | ~~Cock Worship~~ | ~~Biting~~
> 
>  **Pairing:** US!Papyrus/Reader
> 
>  **Additional Kinks:** Brat-taming, aggression kink, d/s overtones

You were…frustrated.

You were horny—so sue you, you were human, it was allowed!—and you’d tried everything, absolutely _everything_ to get your boyfriend’s attention.

Three suggestively-eaten popsicles, five unnecessarily-dropped items you bent over to pick up, and one trip across the living room in only your sexiest underwear later, and he was still just lounging there on the couch, reading a book.

You finally give up and go for broke.

“ _Papyrus._ ”

He angles his skull toward you just a little bit, but doesn’t tear his lidded eye-sockets off his book.

“‘sup, hon?”

“I want to have sex,” you say bluntly.

“cool, go for it,” he replies, flipping a page. “try out that new toy you got, let me know how it works.”

You fold your arms over your chest. “ _With you,_ bonehead.”

“mmm. can you wait a little bit? i wanna finish this chapter.”

Oh, that rat-bastard. He _still_ hasn’t looked up at you, and you…

You’re at the end of your patience with this skeleton.

And you have one ace left up your sleeve.

“Papy, come on,” you plead, putting the barest hint of a whine into your voice. “You can read your book anytime. Don’t you wanna have a little fun… _daddy_?”

You watch Papyrus go completely, eerily still. His bony fingers are actually frozen in mid-air for a moment…until he seamlessly goes back to his reading a moment later.

“careful, hon,” he warns you, deceptively casual. “playin’ with fire.”

Don’t you know it. 

There was a reason you didn’t break out _that_ pet-name often. The last time you’d done it, you couldn’t sit right for a week—actually, legitimately _couldn’t_ thanks to the bruising on your soft, human ass from a hard monster pelvis.

Something about that name drove Papyrus _wild,_ and your normally lazy, ‘can’t be bothered to take your pants all the way off’ boyfriend just changed when he heard it. It reached somewhere deep into his psyche and _poked_ until he was suddenly displaying more dominance than you’d thought he even _had_ and wrecking you within an inch of your life.

You knew very well that if you said it again, you were going to need a very good cushion, very soon.

But he’d left you with no choice.

You edge a little closer to the couch. “I don’t wanna play with fire,” you say. “I wanna play with _daddy._ ”

Papyrus calmly shuts his book. He sits up and carefully sets it down on the coffee table, taking one deep breath in, and then out.

And then he’s _on_ you.

He moves so fast your eyes actually can’t process it, making it look to you like he’d just clipped through the couch like a video-game glitch, slamming you up against the wall. He’s got both of your wrists in his hands and his teeth at the back of your neck like a threat and a promise all at once.

“needy fuckin’ human,” Papyrus grumbles at you, practically a growl. “can’t even let daddy finish a chapter, huh? you gotta have it _that_ bad?”

You shiver at the dark heat in his tone. “Yes, daddy,” you say. “I need it, I’m sorry…”

“nah, you’re not.” You squeak as he grinds his hips against your backside. You can feel how hard he is, he _makes_ you feel it. “but you’re _gonna_ be…”

You don’t doubt it. You know Papyrus isn’t letting you walk away from him until you’re completely destroyed.

You know he isn’t letting you _walk_ away from him at all.

You can’t wait.

When he bites down on your shoulder and yanks down your underwear, all you can do is moan.

“Thaaaank you, daddy…!”

**Notes for the Chapter:**

> I headcanon US!Papyrus as a very chill dude...most of the time. He has his buttons, you just have to know where they are if you want a real reaction out of him. ;3


	7. Experiment (UT!Papyrus/Reader, Body Swap)

**Notes for the Chapter:**

>  **Day 7:** ~~Praise-kink~~ | _Body Swap_ | ~~Aphrodisiacs~~ | ~~Incest~~
> 
>  **Pairing:** UT!Papyrus/Reader, background implications of Alphyne (not enough to tag for)
> 
>  **Additional Kinks:** Slight strength kink

_“A-again, I’m **so** sorry, you guys, I’m working on it, I s-swear, it should, um…it should only be another c-couple of……hours?”_

“IT’S PERFECTLY ALRIGHT, ALPHYS,” Papyrus assures the stuttering lizard through the speaker phone. “WE’RE BOTH FINE AND THAT’S THE MOST IMPORTANT THING! WE CAN MOST CERTAINLY WAIT FOR A SAFE REVERSAL.”

It’s a bit of a surreal experience for you having to _watch_ your boyfriend’s mannerisms play out on your own body—the way he broadly gestures with your hands and how he cocks your hip out just so.

Of course, it was a lot more bizarre for you to be in _his_ body, without any of the skin or muscles or organs you tended to take for granted.

You suppose you signed up for this kind of weirdness when you started dating a skeleton monster in the first place, but an accidental full-soul-swap from an experimental device in Alphys’ lab hadn’t exactly been on your radar of, ‘What To Expect When Boning A Skeleton.’

But you know it definitely was an accident and you hate for poor Alphys to feel so bad about it, so you put your two cents in as well. “Yeah, don’t rush, Al, we’re okay. Just take your time and figure it out, nobody’s in a hurry.”

_“…gosh, you t-two are so sweet. I’ll g-get back to work and Sans said he’d stop by to help soon, so…! It really shouldn’t be that much longer. Ganbatte!”_

And with that she hung up the phone.

You sighed, your…ribcage? expanding and contracting and you had no idea how that was happening without a muscular system, to say nothing of the lungs you definitely didn’t have right now to hold a breath.

“Godspeed, you funky little otaku,” you mutter. “How are you holding up, Papyrus?”

You turned and your eye-sockets went wide at the sight of Papyrus with his… _your_ hand up your shirt.

“Uhhh… _what_ are you doing?!”

“IS IT NOT OBVIOUS?” Papyrus wondered innocently. “I WAS WONDERING ABOUT THE SENSITIVITY OF YOUR NIPPLES. I’VE NEVER HAD NIPPLES MYSELF, NOW SEEMS LIKE THE PERFECT TIME TO INVESTIGATE!”

“Does it really?” you wonder. “When we’re both having a literal out-of-body experience?”

“YES, EXACTLY!” Papyrus raised an eyebrow at you—he’d gotten the hang of manipulating your facial muscles quick. “HAVEN’T YOU EVER BEEN CURIOUS ABOUT _MY_ BODY?”

You……definitely had, you’ve been _very_ curious.

“WELL, NOW YOU’RE IN IT! AND WE’RE STUCK THIS WAY FOR A FEW HOURS, POSSIBLY ANOTHER DAY OR SO IF ALPHYS IS ACTUALLY WAITING ON MY LAZY BROTHER TO FIX THE MACHINE. WE MIGHT AS WELL HAVE SOME FUN WITH IT WHILE WE CAN!”

You think you know where he’s going with this, but just to be sure… “You want to get freaky?”

“I’M SO GLAD YOU ASKED!” Papyrus exclaimed. “YES, THAT SOUNDS LIKE A WONDERFUL IDEA!”

Of course it did, it was his idea.

“THINK ABOUT IT,” he coaxes, “I’D BE ABLE TO FIND OUT ALL OF THE ABSOLUTE BEST THINGS YOUR BODY LIKES BECAUSE I’D BE EXPERIENCING IT FIRSTHAND—AND VICE VERSA!”

Oh. ……… _Oh._

Papyrus looks at you very seriously. “BECAUSE OF THIS ONE LITTLE MISHAP,” he says, “WE COULD VERY WELL BECOME THE GREATEST LOVERS IN THE ENTIRE WORLD. I MEAN, WE WERE ALREADY PRETTY GOOD BEFORE, BUT I THINK THIS WOULD DEFINITELY PUT US OVER THE TOP!”

“You don’t think this is an inappropriate use of Alphys’ technology?”

Papyrus scoffs. "OH, PLEASE, LIKE THIS ISN’T EXACTLY WHAT IT WAS DESIGNED FOR? ALPHYS JUST EXPECTED THE FIRST TRIAL WOULD BE _SHUFFLING SCALES_ INSTEAD OF RATTLING BONES!"

You laugh a little, but…hell, he’s got a point. “Okay, okay, you talked me into it, go nuts.”

Papyrus does a fist-pump that makes him (you?) look positively adorable and dives right in.

There’s something endearing that the second thing he tries in your body is a dramatic hair-flip, but the third thing…

“Hey, wait a minute, don’t spank my ass!”

Papyrus smirks up at you. “WHY NOT? WHAT ARE YOU GOING TO DO ABOUT IT?”

The angle of that cocky little look makes it finally, really click for you.

You’re in _Papyrus’_ body: you’re bigger than him.

A fact you test out with much delight by simply reaching down, picking him up, and plopping him down onto the kitchen counter with ease.

Papyrus looks at you with wide, startled eyes that you’d only ever seen before in a mirror. He has a hand to your chest like he’d be clutching his pearls if you’d been wearing any when you switched.

“OH MY GOODNESS,” he breathes. “YOUR BODY _REALLY_ LIKED THAT.”

You really liked it, too. You can feel Papyrus’… _your_ magic stirring in your soul, coalescing in your pelvis, and you think the grin you warp Papyrus’ skull with must look positively _feral._

You hope Alphys is taking a good, long anime-break right about now.

You’re gonna try to give Papyrus’ dick some ‘extra features’ that you just _know_ your body will love.

**Notes for the Chapter:**

> Was originally going to do 'praise kink' for this day (because it's Papyrus, you cannot tell me that skeleton doesn't having a _raging_ praise kink), but it didn't really click for me... luckily 'body swap,' worked out! ;D
> 
>  
> 
> ~~Also.........what even is the point of an ecto-dick if it isn't customizable?~~


	8. Full Up (HT!Papyrus/Reader, Fisting)

**Notes for the Chapter:**

>  **Day 8:** ~~Blood/Gore~~ | ~~Prostitution/Sex Work~~ | _Fisting_ | ~~Hate-fucking/Angry Sex~~
> 
>  **Pairing:** HT!Papyrus/Reader
> 
>  **Additional Kinks:** Communication during sex, slight size kink

You’re controlling your breathing.

You’re inhaling in strong, deep breaths and exhaling the exact same way, trying to keep yourself relaxed and steady.

It was hard to do when Papyrus had four of his big, long fingers pressing in and out of your body, but you were managing it.

“You’re Absolutely Incredible,” he speaks from behind you. “I Really Wish You Could See This… Maybe Next Time I’ll Record It For You, What Do You Think?”

You huff out a little bit of a laugh. “Ask me again when you don’t have your whole hand inside me.”

“You Know Very Well This Isn’t My Whole Hand Yet!” He leans forward and nuzzles a toothy skeleton kiss right between your shoulder blades. His braces scrape at your skin a little bit, but you don’t mind. “Is This Your Sassy, Indirect Way Of Asking For More?”

Papyrus already has all of his fingers in you. You know his thumb is next and you already feel so, so _full_ …

But you’d been working up to this for a long time.

You were ready.

“Mmn, go for it, big guy…”

“That’s My Human,” he coos at you, and you feel a flare of pride in your chest even as he tucks his thumb in alongside his fingers and…

Oh…

Oh, _stars._

The stretch is something you almost don’t have the words to describe. You’re so _hot_ and you feel sweat beading all along your back as Papyrus sinks his hand into you up to the wrist. You jolt when he gives those long, spindly fingers of his a playful little wriggle that sends a buzz of unexpected pleasure up to your brain.

“Don’t tease,” you snap at him and he laughs.

“Nyeh-Heh-Heh, I’m Sorry, Sunshine, I Couldn’t Resist.” He settles his hand on your ass-cheek and you feel the way you barely fill out his palm. He’s that stupidly huge and you have his other hand _in you_ right now. “This Really Is Amazing… I Can’t Believe You’re Actually _Taking_ This.”

You could hardly believe it yourself…but this was a long time in the making. It was _wild_ what muscle training and a ridiculous amount of lubricant could accomplish.

“You’re So _Pink_ Inside,” he murmurs wonderingly, “So _Hot_ …”

Papyrus pulls out of you and you moan at the unexpected loss, the ache you feel where you’re suddenly empty…

…only to go still as you feel the bones of his clenched fist nudging against you.

“Are You Ready?”

Another deep breath, in and out.

“Yeah, m’ready.”

Your back arched as he pressed back into you, his knuckles dragging against every sweet spot you had inside you and making you shiver and moan a _lot_ louder than you meant to.

“Do You Like That, Sunshine?” he asks you. “Is It Too Much? Am I Hurting You?”

Ohhh, Papyrus. Sweet, respectful, caring Papyrus.

Anybody who thought he was just a huge, creepy monster had no idea what they were talking about. He was your big, lanky sweetheart and nothing was going to change that, not even the fact that his hand was so deep inside you right now that he could probably use you like a puppet.

“In order: yes, no, _hell_ no, and don’t you dare stop!”

So saying, you squeeze your inner-muscles as best you can, making Papyrus jump to feel you fluttering so enticingly where you’re stretched around him.

“Oh, As You Wish, My Human,” he purrs.

You know it’s going to be a long night.

**Notes for the Chapter:**

> All the other prompts for this day seemed so dark and/or mean... Like I joked to a friend, I didn't really have any other choice but to go for the option where I write a loving, wholesome fisting session. ¯\\_(ツ)_/¯


	9. Napoleon (US!Sans/Reader, Bondage)

**Notes for the Chapter:**

>  **Day 9:** ~~Titfucking~~ | ~~Sthenolagnia (Strength/Muscles)~~ | _Bondage_ | ~~Lingerie~~
> 
>  **Pairing:** US!Sans/Reader
> 
>  **Additional Kinks:** D/s dynamics, possessiveness

“THERE, NOW. COMFORTABLE?”

What a question.

Your arms were stretched out, cuffed to the bedposts so tightly that you couldn’t even move them. Your legs were folded and roped into a perfect frogtie without so much as an inch of give in the knots. You were completely and totally exposed, bound and nude on Sans’ bed.

Really, how comfortable could you _be_?

…but then again…the cuffs on your wrists were padded and there was minimal strain in your shoulders from the position. The ropes were snug, but not rough or biting too deeply into your skin.

All things considered…you _were_ pretty comfortable.

“I guess,” you answer, and Sans smiles.

“PERFECT. I’D HATE FOR YOU TO GET AWAY, BUT THE LAST THING I WANT TO DO IS HURT YOU.”

He climbs up to join you on the mattress, prowling over to your restrained body.

“NOT WHEN I CAN MAKE YOU FEEL _GOOD_ INSTEAD…”

Sans strokes a hand along your side, slow but firm. When he leans down to kiss you, you welcome him and he makes a pleased hum into your mouth.

You’d known from the moment you met Sans that he was a little bit of a control freak. Everyone else seemed to see a cute, innocent skeleton with bright eyes and a chipper grin; sometimes even mistaking him for a child, but you never had.

You knew right away that Sans was a man who wanted to be in charge, who got a real _thrill_ out of calling the shots and taking the lead in anything and everything.

You hadn’t been surprised when he told you he’d been gunning for Captain of the Royal Guard in the Underground, and you hadn’t been surprised when he asked if you’d let him tie you up.

A classic Napoleon complex, but you were hardly complaining about it.

Sans’ fingers slipped between your legs and you gasped as he stroked you there. His touch was light, skimming, _teasing,_ and when you arched your hips up for more, he pulled away entirely.

“HEHEHEH…YOU’RE ADORABLE,” he cooed fondly. “TELL ME WHAT YOU WANT.”

“Touch me,” you say.

Sans pulls back even further, a browbone raised. “OH? IS THAT HOW YOU TALK TO ME?”

Your cheeks heat a little at the gentle reminder. He’d asked you to call him, “Sir. Touch me, _sir._ Please.”

His grin broadens. The bright cyan glow of his eye-lights is intense and for a moment, you’re glad you’re doing this with the lights on.

In the dark, he’d look like nothing so much as a predator stalking his prey.

“YOU’D LIKE THAT, WOULDN’T YOU?” he muses. “YOU’D LIKE ME TO TOUCH YOU, TO GET YOU OFF… YOU CERTAINLY CAN’T DO IT YOURSELF, CAN YOU?”

Of course you can’t. You can barely wriggle and Sans knows that damn well.

He’s the one who tied the knots that hold you, and he’s never been anything less than _thorough._

“No, sir,” you mutter. You know he expects answers when he asks you a question.

You watch as he pulls out his cock, slick and dripping with magic.

“I’LL DO MORE THAN TOUCH YOU, DARLING,” he says and almost before you know what’s happening, he’s back on top of you, mashing his teeth against your lips.

Sans hilts inside you suddenly in one rough thrust and you yelp. You can’t brace your hands on his shoulders or wrap your legs around his hips or do anything at all.

Sans has made absolutely sure of that and you shudder as he starts to move inside you in earnest, fucking you hard as you impotently writhe beneath him.

“YOU’RE MINE,” he pulls back to pant at your ear. “I’M GOING TO MAKE YOU FEEL SO GOOD YOU’LL NEVER _FORGET_ IT!”

He’s off to a fantastic start—you think you’re already seeing stars.

“Yes, sir,” you moan. “Thank you, sir…!”

“GOOD HUMAN,” he laughs. “ _MY_ HUMAN…” 

**Notes for the Chapter:**

> Ultra-dom US!Sans? In _my_ Kinktober fic? It's more likely than you think...


	10. Open (UF!Sans/Reader, Bonds [Telepathic or Empathic])

**Notes for the Chapter:**

>  **Day 10:** ~~Hair-pulling~~ | ~~Waxplay~~ | ~~Micro/Macro~~ | _Bonds (Telepathic or Empathic)_
> 
>  **Pairing:** UF!Sans/Reader
> 
>  **Additional Kinks:** Strip-tease (sort of), affection

“So…how is it different from our bond now?” you had asked. “Like, ‘right this second’ now?”

Sans grimaced a little. You think if he had any regrets about taking a human as a mate, it was this: having to actually _explain_ things that any monster would just _know._

But he always took the time to do it anyway, so you imagine it’s not a very _big_ regret.

“right now, it’s…not closed,” he’d said haltingly, “but it ain’t open, either, it’s like… it’s like you an’ me are in a room together, but…there’s a big curtain in the middle. it ain’t thick, i know yer there, i can hear ya’ sometimes, if yer loud, but there’s…there’s still a big honkin’ curtain in the way.”

“And you want to get rid of the curtain.”

Sans had looked so _shy_ at that summation, his cheekbones flaring pink and refusing to meet your eye. “not _permanently,_ ” he’d rushed to add, “i know it’s…obviously, ya’ need yer privacy, everybody does, even from yer mate sometimes, but i…i wanna hear you. i wanna feel you…”

It was never very hard to remember why you’d agreed to soul-bond with this skeleton in the first place.

“Would I feel you back?” you’d wondered.

Sans had just shrugged at that. “realistic answer…? no.” He’d rubbed at the back of his neck a little. “nothin’ about you specifically, just…humans’ve lost touch. with that, with magic an’ soul junk. if there’s anythin’ at all, it’ll be faint on yer end, you’d prolly miss it.”

So, like the moment you’d bonded with him when you’d felt nothing but a faint buzz in your chest until Sans literally took hold of your soul and poured his magic into it. This was something more for him than for you.

You were so glad he’d asked.

“Care to make it interesting?”

Sans never could resist anything that sounded like a wager, and that was how you’d ended up here—perched excitedly on the bed with your mate in front of you, red as a tomato and he hadn’t even started yet.

“i still don’t see what yer gettin’ out of this,” he grumbled at you, but you just grinned.

“You’re about to, though, aren’t you?” Your bond was open, _all_ the way open, no curtains to be found here…

…and in exchange, you were going to watch Sans undress.

“Trust me,” you say encouragingly. “When have I ever not known what I was doing?”

“lotsa times, doll,” Sans says flatly, but you know it’s fond and he stops arguing with you.

He shrugs off his jacket first and that has your full attention. Sans looks a little smaller without it, a little softer, and the exposed planes of his still-broad shoulders make you want to reach out and pull him closer to you.

Sans goes still, his expression one of surprise. “…seriously?”

Oh, looks like he heard that thought!

You just smile, wordlessly urging him to continue.

Sans moves on to his sweater, hesitantly peeling it off. You know he hates this part of intimacy the most—he thinks the nicks and scrapes all over his ribs from a life of near-misses are a turn-off to you, that the ecto-body that forms beneath them when he has excess magic doesn’t have a six-pack and therefore isn’t as sexy as he _could_ be.

You think it’s cute that he’s shy…and silly that he thinks you give a damn. So what if he’s a fat skeleton? They’re called ‘love _handles_ ’ for a reason.

The mental image that sparks is such that you’re not very surprised when Sans suddenly looks at you with _very_ wide eye-sockets and a _very_ red skull.

“doll, what the…!”

“Keep going,” you playfully chide. “Don’t you wanna know what I think about your dick?”

Sans just stares at you for a long moment. A droplet or two of sweat starts to bead on his skull, but eventually…

His claws move to the waistband of his shorts.

In the back of your mind…maybe your soul? You catch a snippet of something, so faint and faded that you’re almost not sure you heard it.

But you did.

_……so fuckin’ **hot,** how’d a goon like me get so **lucky**???_

It makes you smirk. “Aww, baby,” you coo, “you’re not a goon. A _numbskull_ , maybe, but not a goon.”

Sans needs a second to process what you just said.

Once he does, you feel a burst of delight in your chest, the primal _joy_ of being connected with your lifemate on the deepest of levels, the thing that every monster, no matter how jaded and angry and miserable, spends their whole life _yearning_ for…!

When Sans practically tackles you onto the bed a split-second later, you catch him easily with open arms, but of course you do.

You felt it coming.

**Notes for the Chapter:**

> I'm really earning that 'Porn with Feelings' tag, huh? Is there a tag for 'More Feelings Than Porn' so I can earn that, too?
> 
> It's not my fault, UF!Sans just needs a lot of love to get kinky, I'm sorry, I don't make the rules.
> 
>  
> 
> ~~Yes, I do, and the rule is: if he doesn't love and trust the person he's with, UF!Sans is a basic vanilla bitch.~~


	11. New Things (SF!Papyrus/Reader, Sounding)

**Notes for the Chapter:**

>  **Day 11:** ~~Object Insertion~~ | _Sounding_ | ~~Cross-dressing~~ | ~~Tribadism/Scissoring~~
> 
>  **Pairing:** SF!Papyrus/Reader
> 
>  **Additional Kinks:** D/s dynamics, obedience kink

It was a lovely evening in.

You were on the couch, feet propped up on the ottoman while you idly clicked at a cute cat-game on your phone. You were relaxed and comfortable, even with the way your bony boyfriend was heavily leaning against your side, fiddling with a complex Rubik’s cube to pass the time.

Papyrus had been sliding further and further down your arm for the past hour and would land in your lap soon at this rate, but neither of you seemed to care.

It was sweet; almost sickeningly domestic.

That’s probably why you spoke up.

“Hey, Rus?”

Papyrus angled his skull up to look at you, but his fingers were still twisting and clicking at his dodecahedron. You half-wondered what kind of color-pattern he was trying to make with it—if he were actually trying to solve it, he’d have done so within a minute of picking the thing up—but ultimately, you didn’t really care.

“Do you wanna play?”

Papyrus dropped his puzzle instantly like so much garbage. With lightning speed, he practically combat-rolled off the couch, startling you into sitting upright just in time for him to settle into a kneeling position at your feet.

Your delighted laugh made him puff his chest out a little. You knew he took pride in his ability to please you, his loyalty unshakeable and his submission total the very _second_ you asked for it.

You also knew quite well why that was, what you had to offer this big, battle-scarred monster that not a single lover before you had ever bothered to give him.

“Such a good boy,” you said sweetly, reaching down to tilt his chin up towards you. Papyrus pressed his skull against your hands, squinting happily at you while your thumbs stroked along his cheekbones, his jaw, his shiny gold fang.

Your skeleton was a _sucker_ for a soft touch.

He’d confessed to you once, in a rare moment of candor, that he’d probably let you do anything, anything at all to him that you wanted to do, no matter how wild or fucked up it was. He trusted you _that_ much when you took the reins, knowing that no matter how completely you took him apart, you’d put him back together again and make it all okay.

You were determined to _never_ make him question that.

“I got a new toy for you,” you told him. “Do you want to try?”

“yeah,” Papyrus hastily agreed, not knowing and probably not caring what it was, the incorrigible hedonist. “yes, please.”

You bent down and pressed a quick kiss to his nasal ridge.

“Thought so.”

With a nudge from your foot, the ottoman scooted along the floor, a little away from the couch for extra room.

You stood and instructed, “Lie down, pants open, dick out. You can touch yourself if you want to while I’m gone, but you stop when I get back. Clear?”

Papyrus didn’t bother to hide the eagerness in his expression. “crystal,” he promised.

You turned and left the room to get Papyrus’ gift. You didn’t check that he would do as you’d told, _knowing_ he would.

By the time you returned, it was to exactly the sight you’d asked for, Papyrus’ lanky body draped backwards over the ottoman, his legs spread wide for balance and his cock in his hand.

You took a moment to admire it first.

It was a lovely cock, girthy and _long_ to the point that you’d once accused him of making it bigger to impress you, but he’d blushed and sworn up and down that it just formed like that on its own.

You believed him by now and that was why you’d bought this special toy: his dick was just too _perfect_ for it.

The second you cleared your throat, announcing yourself, Papyrus let go of your prize and fisted his claws in his jeans.

And his eye-lights shrunk when he saw the stainless steel rod you mischievously waggled at him.

“Still wanna play?” you asked.

A shudder visibly wracked his body, but you weren’t surprised when Papyrus answered you with a very clear, _“yes.”_

You knelt beside him, taking his gorgeous purple cock in hand and giving it a few good pumps that made Papyrus start to pant and squirm a little…

…but he didn’t buck up or try to do anything with his hands.

You hadn’t told him that was allowed.

“ _Good_ boy,” you purred, “ _so_ good for me,” and you felt him stiffen even more beneath your fingers.

Swiping a packet of lube from the pocket of his jeans, warm from his body-heat, you tear it open and drizzle it all over the sound before pressing it to the head of his dick, ever so gently kissing up to the slit.

You look at him with your eyes lidded and your mouth twisted by a sinful smirk you just can’t restrain.

“You’re sure?” you wonder. “Last chance…”

Papyrus shivers. “i love you,” he breathes.

You let go of the rod.

It’s thin, for beginners, and with the way eased it slips right in, filling Papyrus’ cock like nothing ever had before.

“mmngh…!”

Papyrus tosses his head back, eye-sockets clenched shut. His whole body rattles under the strain of staying still in the face of the unfamiliar sensation even as you admire the line of steel you can see through the semi-transparent curve of his dick.

Just one of the perks of having a lover with ectoplasmic genitalia.

“How does it feel, baby?” you have to know. “Does it hurt?”

“mmm…n…no,” he huffs eventually. “it…s’weird… _tight_ …”

“Bad?”

“……”

Papyrus looks down at his cock in your hand, at the steel ball at the end of the sound just peeking out from the tip.

“…touch me more? an’…an’ find out?”

That was a request you were happy to fulfill. You knew it wouldn’t be long before Papyrus begged you to take it back out of him, so he could come.

You wonder how long it’ll take him to ask you to buy more of these to play with, but by the look of _ecstasy_ on his face as you gave his dick a good squeeze…?

You think the smart money is on a week, tops.

**Notes for the Chapter:**

> This was a new one for me, had to research it a little. Not sure how I feel about it personally, but if any skeleton would appreciate it, I feel like it would be the ever-freaky SF!Papyrus. ¯\\_(ツ)_/¯
> 
> Like everyone and their grandmother, I have my own version of the Swapfell AU in my head so here's a quick and dirty cheat-sheet based on the three most popular versions: aesthetics of SF Purple/SF Gold, personalities of SF Gold/SF Red.


	12. Hero (UF!Papyrus/Reader, Costume)

**Notes for the Chapter:**

>  **Day 12:** ~~Licking~~ | ~~Pet Play~~ | ~~Rimming/Analingus~~ | _Costume_
> 
>  **Pairing:** UF!Papyrus/Reader
> 
>  **Additional Kinks:** Roleplay, emotional validation

You laid there on the silken sheets of the bed, completely motionless.

Your fluffy, laced up gown is snug in the chest and you want nothing more than to loosen it. The sunlight streaming in through the window is bright and irritating, even to your closed eyes, and you want to draw the curtain. The fragrant scent of the rose petals scattered all around you was intense and cloying and you’d love to be able to gather them up and throw them away to be rid of the smell.

But you don’t move a muscle: you can’t. You’re stuck, awaiting your rescue from this storybook prison, your knight in shining armor.

You think you hear him coming, though, and soon the door creaks open.

There’s a faint exhale, but no words, your rescuer momentarily struck dumb by your ethereal beauty. It passes and you hear deliberate metallic footsteps approach you—you’re almost free and you pray you don’t spoil the moment.

Hands encased in gauntlets settle on your body, one at your hip and the other curling beneath your neck, pulling your limp body up and finally, it’s time.

_True love’s first kiss._

You come to life with a breathy sigh as the knight’s sharp teeth press gently against your mouth. Your hands come up to ever so daintily light on the shiny black metal of his pauldrons as you kiss him back, slowly as a dream.

When your eyes flutter open, you see the scarred skull of your savior staring down at you.

“You came for me,” you say, like you just can’t believe it.

“OF COURSE,” he says. “AS IF I COULD EVER LEAVE SUCH A BEAUTY IN PERIL…”

You frown a little, confused. “But…the quests…the long voyage…the sea-monster…!”

“DEALT WITH,” the knight assures you.

His armor is accordingly scuffed and dented, his grand crimson cape tattered and torn…

But you find him no less dashing than you did the moment he kissed you awake.

“Such peril…all for me?”

He smirks and you only admire him more.

“ANYTHING,” he says. “I WOULD DO ANYTHING FOR BUT A MOMENT OF YOUR FAVOR, MY DEAR.”

He grasps your satin-gloved hand and nuzzles it, a gentleman’s kiss.

You know what you must do; what you _want_ to do with all your being.

“For a knight so brave, you can have more than my favor.” You cup his jaw, staring deeply into the fetching red of his eye-lights. “ _Much_ more.”

He looks intrigued. “HOW MUCH MORE?”

You smile, just a hint coquettishly. “ _All_ of me,” you say without hesitation. “Bed me, here and now if you desire—I’m yours.”

He seems startled, but he doesn’t back away from you, not one inch. “SUCH PROMISES,” he hums. “ALL FOR A STRANGER?”

“All for my _hero_ ,” you correct him.

You watch the proud bravado on Papyrus’ face falter.

 _That_ wasn’t in the script he’d given you.

But you had to say it: he’d put you in this dress, set the scene, killed time by running errands and having a sparring session with Undyne in his full Captain’s regalia to look properly majestic and battle-worn, and you _weren’t_ supposed to know what all this was about?

Papyrus…your strong and amazing Papyrus at the center of his tough, cynical exterior…

You knew that before his world had made it safer to be a villain, what he’d wanted most of all was to be a hero.

Whatever Papyrus’ next cool, manly line had been, it was obvious he’d forgotten it, and he just stared at you with shock and mounting anxiety.

Was he afraid you were going to laugh at him? Tell him he was a silly dreamer? Or worse, a violent bully who could _never_ be a knight in shining armor, not when his breastplate was blood-stained and black?

You didn’t intend to make him wait, dwelling in such cruel thoughts.

“Take me, hero,” you entreat, pulling Papyrus flush against your body. “Show me your warrior’s spirit, seduce me with your valor, and give me the name of the man I love so I can call it for you in perfect bliss!”

You had skipped _way_ ahead in the dialogue there, but you didn’t want to make _either_ of you wait just now.

You wanted him—and you felt like he _needed_ you—and you weren’t about to let another three pages of flowery seduction put that off one moment longer.

Your Papyrus was a resilient one. He only took a handful of seconds to shake off his alarm and slip right back into character with a grateful grin.

He wasn’t off the hook, you would be _showering_ him in affection and affirmations later on, but for now…

“I AM THE GREAT PAPYRUS,” he boldly proclaimed, one hand dexterously undoing the lacing of your bodice, “AND YOU’LL KNOW IT IN YOUR VERY SOUL BY THE TIME I’VE FINISHED WITH YOU.”

You couldn’t wait.

…you really wanted this dress off.

**Notes for the Chapter:**

> .........we're back to the feelings again, I'm ~~not that~~ sorry, I just love that sweet, sweet emotional validation, and if anybody could use it, it's the big pointy tsundere that is UF!Papyrus.  >.>


	13. Family Way (HT!Sans/Fem!Reader, Creampie)

**Notes for the Chapter:**

>  **Day 13:** ~~Weight Gain~~ | ~~Distant/Distracted Sex~~ | ~~Gags~~ | _Creampie_
> 
>  **Pairing:** HT!Sans/Fem!Reader
> 
>  **Additional Kinks:** Breeding kink, mating cycles/in heat

Sans didn’t wanna stop.

You were so sexy and incredible and amazing, just _looking_ at you right now lit a fire in his bones. He was itching to sink into you; his fingers, his teeth, his cock, any way and anywhere you let him, and you let him do a _lot._

He wanted nothing more than to imprint himself all over and on and _in_ you until there could never be any question _again_ about who your mate was…

…but he’d already done a pretty good job and from the looks of you, you _really_ needed a break.

You were lying lordosis in front of him, your ass raised in presentation while your entire upper-body had long since collapsed to the bed. Your perfect skin was drenched in sweat and marked up with uncountable bites and bruises that made his soul just _thrill_ with pride.

And you were _dripping._

Sans had fucked your pretty pink pussy _raw_. The rough pounding he’d given you had left you gaping wide, wide open and from your wrecked core he could see his come oozing out of you in long, slow trickles.

At first he hadn’t wanted to stop fucking you, pumping his seed so deep into you that you felt it all the way into your belly, but now?

He didn’t want to stop _watching_ you.

Every time you shuddered, still panting to catch your breath, your tired muscles gave a little twitch and Sans had the pleasure of watching a bit more of his thick blue come drain out of you. The sticky puddle on the sheets beneath you was spreading and spreading, but he just kept watching, utterly riveted.

How many times had he come inside you by now for there to be _so much_?

He knew it had to be a lot—he wasn’t even concerned that you weren’t trying to keep it in, he’d filled you up so well that you’d be leaking him for days, no matter what.

How far inside you had he gotten it? All the way to your womb? _Inside_ of it?

Stars, he hoped so.

Sans had never felt such deep, primal joy in his life as the moment you told him you were ovulating, and _right_ on the cusp of his heat.

“god, baby, ya’ look so fuckin’ _good,_ ” he told you.

A weak little groan was his only answer. You were too exhausted to do anything else, and Sans felt his grin turn feral.

You jolted hard when he grabbed you by the ass-cheek and shoved his fingers into you with a wet squelch.

You were so _sore,_ but Sans either didn’t care or _couldn’t_ care through the fog of his rut. All you could do was whimper and squirm as he rubbed at your insides, massaging his come into your tender walls.

“ya’ know it’s done, right?” he purred, sounding satisfied. “yer pregnant, sugar. _gotta_ be after all’a that.”

You knew he was right. You practically felt it in your soul, and you whined while Sans chuckled and trailed a hand down to your belly, petting you there, too.

“ya’ excited?” he wondered. “ _i_ am. can’t wait to watch it happen, see how _big_ ya’ get with yer womb stuffed fulla my kids…”

“Yuh…you…” You swallowed, hoping some moisture would help your hoarse throat form the words. “You’re gonna be a great dad…”

Sans stilled behind you.

You knew how badly he wanted to hear that, how much he _craved_ a big, happy family after everything he’d lived through.

You wanted it too, for _both_ of you.

“I love you, baby,” you breathed. “I love you, I wanna have _so_ many kids for you…!”

And suddenly Sans was on top of you, draped over your back again like he had been for hours until this little reprieve.

“you will, starshine,” he rumbled at you, on the edge of a growl. “ya’ think i’m gonna stop at one? ya’ think i ain’t gonna _keep_ knockin’ you up?”

You yelped as the blood-hot tip of his cock prodded against your aching folds, slowly nudging into you again with a positively filthy sound.

“m’gonna put my seed in yer belly as long as you can carry it,” he told you, brooking no argument. “ya’ won’t remember what it’s like _not_ havin’ a baby in ya’, an’ if ya’ do, i’ll just fill ya’ up again ‘til ya’ forget… my own lil breedin’ sow…”

You shivered and moaned while Sans just laughed and started to move. It still hurt but the more he fucked you, the more your pleasure started to drown out the pain.

“ya’ like that? ya’ wanna be a mommy _that_ bad?”

God help you, you do, you _really_ do.

You know Sans will take such good care of you.

Even as his own come dribbles out of you with every thrust, even as he rattles with the urge to fuck you rougher, harder, _more_ , you can see the steady glow of his red eye in your peripheral vision. You can feel him nuzzling sweetly at your neck as he holds himself back, fighting his own instincts so you can actually enjoy this, too.

Sans would never really hurt you in a million years—but especially not when you’re carrying such precious cargo.

**Notes for the Chapter:**

> .................what do you mean, I just dumped all my favorite kinks onto HT!Sans because he's my favorite? That's totally ridiculous.......
> 
>  
> 
> ~~You might not be wrong....whoops...~~


	14. Satisfaction (US!Sans/Fem!Reader, Cunnilingus)

**Notes for the Chapter:**

>  **Day 14:** ~~Asphyxiation~~ | _Cunnilingus_ | ~~Distention~~ | ~~Tentacles~~
> 
>  **Pairing:** US!Sans/Fem!Reader
> 
>  **Additional Kinks:** Thicc(-ish?) reader, minimally described

_‘My favorite thing in bed’?_

It was yet another question about your relationship, in a growing line of them, that your boyfriend was asking you completely out of nowhere.

You couldn’t help but chuckle at this one.

“What is this, a customer satisfaction survey?”

Sans gasped, his eye-lights shifting into those ever-endearing stars you loved so much.

“THAT’S A GREAT IDEA!” he exclaimed. “I’M DISAPPOINTED I DIDN’T THINK OF THAT TO BEGIN WITH, NUMBER SCALES WOULD PROBABLY GIVE ME MUCH MORE USEFUL FEEDBACK THAN ANECDOTAL EVIDENCE… NEXT TIME!”

You laugh. “Sans, seriously, come on, what is this about? Why do you need feedback?”

“……WELL.” Your skeleton’s cheeks go a little blue, his face angling away from you just a little bit. “YOU’RE…YOU’RE MY FIRST SERIOUS RELATIONSHIP,” he admits. “I REALLY LIKE YOU AND IT’S BEEN GREAT SO FAR…I WANT TO MAKE SURE I’M DOING WELL!”

_Awww…your sweet blueberry cinnamon roll._

“You’re doing great, baby,” you promise, “no complaints.”

But you think it’d make him feel better to answer his question anyway, so you think about it. Your _favorite_ thing in bed…

You don’t have to think very long.

“You’re a…a very _cunning linguist._ ”

Sans tilts his head. “…DIRTY TALK?” he guesses. “YOU LIKE THAT THE MOST?”

“No, no,” you laugh. “…Well, yes, but what I meant was, uh…y’know. When you…go down on me…”

“AH, ORAL SEX. …CUNNILINGUS!” He snaps his fingers. “NOW I GET IT, THAT’S A VERY CUTE JOKE.”

You smile. “Well, you’re _really_ good at it. You…ha, you eat pussy like it’s your _job._ ”

Sans frowns at you. “UH…IT _IS?_ I’M YOUR DATEMATE, IF I’M NOT SATISFYING YOUR EMOTIONAL _AND_ PHYSICAL NEEDS, THEN LITERALLY _WHAT_ IS THE POINT?”

“Wish my ex thought like you,” you mutter bitterly. “He always said it was ‘gross’ and never bothered, but he sure expected blowjobs a lot.”

Sans’ skull is scrunched into an expression of sincere distaste and pity. “YOU POINT HIM OUT IF WE EVER SEE HIM. I’LL GIVE HIM A _VERY_ PUBLIC AND EMBARRASSING LECTURE ON RECIPROCITY AND RESPECTING YOUR PARTNER!”

…Well, that made you feel better! You kinda hoped you saw the bastard one of these days, just so that could happen.

“I HAVE TO ADMIT, I’M A LITTLE SURPRISED,” Sans cut into your spiteful thoughts. “I DIDN’T THINK… WELL, I’D HOPED I WASN’T _AWFUL_ AT IT, BUT I DIDN’T THINK IT WAS SOMETHING YOU WERE VERY INTO. YOU ALWAYS SEEMED…HESITANT? WHEN WE TRIED IT BEFORE… I THOUGHT FOR SURE YOU JUST DIDN’T LIKE ORAL.”

“……” Oh boy. “…Well…I like it, I do! I just…get worried.”

“…WORRIED.”

You feel your cheeks darkening.

“…you’re a skeleton,” you say meekly, “and I’ve got these…” You grimace a little, looking down at your accursed thunder-thighs. “……I don’t wanna _hurt_ you…”

Sans followed your gaze, putting together your thought process from your partial sentence. He was quick, you knew it was only a matter of time before he realized what you meant.

“………HEHEHEHEHEH…HAHAHA OH MY _GOD!_ YOU SERIOUSLY GET NERVOUS WHEN I EAT YOU OUT BECAUSE YOU THINK YOU’RE GOING TO CRACK MY SKULL OPEN?”

You blushed harder…and Sans laughed harder.

“OH MY GOD…” He chuckled your name, shaking his head. “I’M NOT A HUMAN, MY BONES ARE _MUCH_ STURDIER THAN YOURS, YOU’RE NOT GOING TO BREAK ME!” His eye-lights were bright, glowing with mirth. “AND IF YOU EVER DID, I WOULD HAVE THE MOST _HILARIOUS_ BATTLE-SCAR STORY IN THE WORLD, CAN YOU IMAGINE? ‘AH, YES, THAT ONE—I GOT THAT CRACK TRYING TO WEAR MY DATEMATE LIKE A HOCKEY MASK, BEST NIGHT OF MY LIFE!’”

You buried your face in your hands, but you couldn’t help but snicker a little, too. “Really? You’re sure?”

When Sans didn’t answer you right away, you looked up…and found him watching you with an eager, almost-predatory smirk.

“WHY DON’T I PROVE IT?”

He dove between your legs like a man on a mission, divesting you of any clothing that was in the way and licking a hot, wet stripe along your entrance with his glowing blue tongue.

_Oh shit, **sin** namon roll…!_

Encouraged by the instinctive buck of your hips, Sans presses his tongue deeper into your folds. You think you can feel it lengthening as it expertly twists inside you, Sans compensating for his lack of lips by enhancing his tongue, but when he undulates it _just_ so against your g-spot your brain shuts off entirely.

You fall back onto your elbows with a startled moan. You’re getting wetter by the second, even as Sans gathers your legs up over his shoulders so he can get even closer, even _deeper_ into you.

The careful graze of his teeth against your outer lips sends a thrill up your spine and you chance a look down between your thighs.

Sans looks utterly delighted to be there. His face is pressed as close to your body as he can get it, with the bottom of his nasal ridge rubbing enticingly against your clit even as his magic tongue curls in and out of you in long, smooth thrusts.

He must sense you looking because his eye-lights flick up to meet yours and you can feel his grin stretch against you.

Holding eye-contact, Sans puffs out a single breath through his nose, right onto your clit.

You jolt immediately, your inner walls contracting around Sans’ still-writhing tongue while your thighs automatically try to clamp shut, squeezing _tightly_ around your lover’s skull.

…but he’s just fine with it, waggling his browbones at you while his chuckle sends _delicious_ vibrations through your entire core.

You can practically hear his smug voice in your head.

_I TOLD YOU SO…_

“Yeah, f-fine, you win,” you pant. “Dumb human, smart monster; you better finish what you started!”

An unnecessary request: Sans _always_ finished what he started and he was happy to prove _that_ to you, too.

_Vigorously._

**Notes for the Chapter:**

> Thick thighs save lives? So do thick tongues...long ones, too. ;D


	15. Messy (HT!Papyrus/Reader, Intercrural Sex)

**Notes for the Chapter:**

>  **Day 15:** ~~Forniphilia (Human Furniture)~~ | ~~Overstimulation~~ | _Intercrural Sex_ | ~~Uniforms~~
> 
>  **Pairing:** HT!Papyrus/Reader
> 
>  **Additional Kinks:** Size difference, voice kink, hinted-at messiness kink

“Absolutely Not!”

“Papyruuuuuus…”

“No! I Don’t Care How Adorably You Say My Name!” he exclaimed. “You’re Not Ready! I’m Not Going To Hurt You Just Because You Refuse To Be Patient!”

You huffed in frustration. As much as you hated to admit it, he had a point: you loved this big, gangly monster to pieces and wanted to show him just how much, but, well…

Papyrus was…proportional. And he just so happened to be twice your height.

He could change the shape and size of his dick a bit, considering it was made entirely of magic, but even at its most unassuming, it was still longer than anything you’d ever taken.

But the training toys you were using were taking _forever_ and you didn’t even want to think about how incredibly pent-up Papyrus was getting after _months_ of cutting off your heavy petting sessions, or only getting _you_ off with just his hands.

“Come on,” you pleaded, “I want to do _something_ for you! At least let me use my mouth!”

Papyrus scoffed. “And I Suppose You’ll Let Me Drive You To The Emergency Room When You Dislocate Your Jaw Because You Don’t Know The Meaning Of Restraint?”

“………”

God, he knew you _so_ well.

You tried to think of something, anything you could say to make this happen…

And then it hit you.

“What if there’s not even penetration?”

You saw the thoughtful, intrigued look on Papyrus’ face and knew.

_Got him!_

And that was the story of how you’d ended up on your back with Papyrus kneeling over you, a smile on your face and lube all over your thighs.

Somehow, he still looked a tad nervous. “Now, You’ll Tell Me If You Want To Stop, Right? And If It’s Weird?”

You just rolled your eyes. “Papyrus, I’m in bed with a skeleton, we’re well past ‘weird.’”

“…Hm. Point.”

Without any further ado, he settled his cock between your legs, grasped both of your knees in one big, spindly hand, and started to move.

You’d never tried this before and you weren’t quite sure what to make of it, or what you were supposed to do, exactly. The friction against your groin and your lower belly where Papyrus rubbed against you was kind of nice, so you tightened your thighs a little bit, trying to get more.

Papyrus let out a choked groan above you and you looked up.

The view was even _nicer._

His eye-sockets were lidded and a deep flush colored his cheekbones. He looked…intent, _heated_ in a way you’d never gotten to see him before.

It surprised you how much it turned you on.

“God, you’re sexy,” you breathed, reaching up for him. “C’mere, come down here, let me kiss you…”

Papyrus obligingly leaned down, but didn’t stop fucking the warm, wet space you’d made for him between your thighs.

“I Didn’t…I Didn’t Expect It To Be This _Good_ ,” he haltingly admitted, even as you pressed a few affectionate smooches along his jaw. “When…When You Said……It Just Seemed So _Messy_ …”

“It is.”

There was no denying that. Everything below your waist right now felt slippery and it was only spreading the more Papyrus rutted against you, but…

“Think about how much _messier_ it’s gonna be when you finally get _in_ me,” you purr against his braces. “It’ll be so tight and hot and _wet_ … You’re gonna _wreck_ me and it’ll be because I _begged_ you to…”

“Nngh!”

You jump to feel a hot spurt of come on your belly, Papyrus giving another shaky thrust or two before slumping forward a little and just barely catching himself from squishing you beneath his weight.

“………did I just _talk_ you off?” you wonder incredulously.

“Well, I Think Your Thighs May Have Had Something To Do With It, Too!”

You snicker a little at Papyrus’ indignant tone. “Yeah, alright, maybe a little. But it was good, right? You liked it?”

“I…Did. Surprisingly.” He looks down at the rapidly cooling stickiness between your bodies and the ridge of his nose wrinkles. “Ugh, It’s So _Gross,_ Though…”

You remember the words you used to push Papyrus over the edge and think that maybe his relationship with messiness is a little more _love_ -hate than just hate.

“That’s what showers are for,” you say easily. “We can go take one right now? See if shower gel works any better than the lube?”

Papyrus squints at you. “This Is Our Sex Life,” he chides, “Not A Poorly-Written Fanfic!”

But he scoops you up and starts carrying you to the bathroom, anyway.

“If You Try To Use Your Body-Butter For Anything Other Than Its Intended Purpose, I _Will_ Leave You To Shower Alone!”

“Mmm, yeah, that’s fair.”

**Notes for the Chapter:**

> My HT!skeles are...very big. It's important to the narrative. Somehow.
> 
> I will not apologize for art.
> 
> And also please practice safe lubrication, everyone, do not use [unconventional substances](http://nikonova.online/2013/08/24/52654/) during sex under any circumstances, please.
> 
> HT!Papyrus, passing by US!Sans from the last chapter on his way to appreciate the reader's thighs: "Ah, I See You're A Man Of Culture, As Well!"


	16. Lucky (UF!Sans/Reader, Body Worship)

**Notes for the Chapter:**

>  **Day 16:** ~~Nipple Play~~ | ~~Frottage~~ | _Body Worship_ | ~~Sixty-nine~~
> 
>  **Pairing:** UF!Sans/Reader
> 
>  **Additional Kinks:** Jealousy, hurt/comfort (yes those are kinks)

“hey. you gonna talk to me, or what?”

You weren’t sure what there was to say. You played dumb.

“About what?”

You heard Sans huff and knew he wasn’t buying it.

“ya’ think i’m blind?” he asked. “ya’ think i don’t see ya’ slinkin’ around like an alleycat? if yer mad at me, ya’ gotta say, you _know_ that.”

It was one of the first big disclaimers Sans had given you when you’d started dating: if you had a problem, you _needed_ to tell him, he was no good at little hints, never had been, he needed the _words_ if you wanted something to get fixed.

But he hadn’t done anything wrong. So you hadn’t said anything.

“I’m not mad,” you shrugged. “Don’t worry about it. It’s…it’s a me-thing.”

It was completely and totally _your_ thing to deal with and it made you feel like garbage that Sans had noticed; that he thought it might be his fault.

You jumped when Sans grabbed you, his claws curling around the back of your neck. They were razor-sharp but he’d never once cut you with them.

“hey,” he said sternly. “if it’s a you-thing, it’s a me-thing.”

In spite of his tough-guy appearance, Sans was always careful with you, always gentle and sweet. He was a great guy, really…

…and he deserved a lot better than you.

“Seriously,” you insisted, “it’s fine. Just…let it go? I’ll…I’ll get over it, it’s not that big a deal.”

Sans just frowned at you, looking _very_ unhappy. He let go of you and took a step back.

“…yer really not gonna tell me. yer really gonna make me do this?”

“……Do what?”

He sighed.

“okay. i tried. ya’ forced my hand.”

Before you could say another word, the world around you faded to black.

And four orange boxes appeared in front of you.

_An Encounter._

You paled, lashing out and hitting ‘MERCY’ to spare him and end it as quickly as you could, but by the look of shock on Sans’ skull, you knew it was too late.

He’d ‘CHECK’ed you, he’d _seen,_ you didn’t know what, but it was more than you wanted him to know and you tensed, waiting for him to say something.

“……th’hell do you _mean_ you ain’t good enough for me?”

You winced. “I…! Forget it, seriously, forget it, it’s not important, I’m…I’m being stupid, I know I am!”

Sans was right in front of you again in the blink of an eye, one hand on your hip and the other tilting your chin up, _forcing_ you to look at him.

“you ain’t stupid, doll,” he said, “but y’ain’t makin’ sense either. where’s this comin’ from?”

You knew the answer. You were embarrassed to say it out loud, but you knew Sans wasn’t going to drop this now. If you tried to clam up, he’d just CHECK you again to get the next step in the conversation.

“I…it’s…that girl. The one that was…hitting on you.”

You’d had a front-row seat to it when you went to pick Sans up from the auto-shop he worked at for your date-night. He hadn’t seen you, but you’d seen him, and you’d seen the supermodel-gorgeous lady that was flirting with him while he worked on her car.

What killed you was that Sans had done absolutely everything right: he hadn’t given her a once-over, hadn’t stared when she’d bent over to show off her cleavage, hadn’t responded to her coy innuendos.

He’d even given her a gruff, “m’taken,” when she finally stopped beating around the bush and asked him out!

But you still just felt… _bad._

“…I’m not…like her,” you said quietly, eyes downcast. “I don’t…have flawless skin and perfect boobs and a hot body… And I know, I know it’s dumb, I know you’re with me and you wouldn’t… I just wish…!”

Sans jerked your chin back up to meet your eyes, demanding, “who the hell says you don’t have a hot body?”

You opened your mouth…but you didn’t know what to say.

Luckily, it seemed like Sans did.

“yer the hottest fuckin’ human i ever seen,” he said.

His hand trailed down from your neck, claws skimming along your chest and belly and making you shiver.

“just lookin’ at’cha turns me on…”

You jumped when his hand curved around behind you once it reached your hip to give your ass a squeeze.

“yer so _soft,_ baby,” he rumbled at you, pulling you flush against his body. “y’feel amazing on me, i can’t get enough of ya’…”

“‘Soft’ is…‘soft’ isn’t usually a good thing, for humans…” you mutter quietly.

He’s too close not to hear you. “humans’re stupid then,” he says, bending to nuzzle at your throat.

You’re sensitive there and he knows it. You start to squirm in his grip.

“y’know how _rare_ ‘soft’ was Underground? everybody, everything, it was all just…hard an’ rough an’ _sharp._ ”

He makes his point with the claws that creep up under your shirt, carefully petting at your belly.

“‘soft’ was a goddamn luxury…an’ i hit the jackpot with you, doll.”

“I…I’m not…”

“yer _perfect,_ ” he insists, “yer perfect for me, i love the way ya’ look, i don’t wanna hear another damn thing otherwise. yer insultin’ my taste, and yer insultin’ my date, them’s fightin’ words.”

That makes you giggle a little. He’s always been good at that.

“You’re gonna fight me?”

Sans pulls back just far enough that he can check you out, from head to toe. His roving red eye-lights make you shiver a little with their intensity.

From the look on his face, you think you’re starting to believe it for the first time—to him, your body is absolutely _incredible._

“mmm, nah. got a better idea.”

He grabs you and in a swirl of void and color, you’re suddenly in your bedroom and he’s nudging you onto the mattress, pawing at your clothes.

“c’mon, off,” he tells you, “ _off_ , i wanna see you, no more hidin’…”

What else can you do?

You help him take your clothes off.

He looks at you once you’re naked, the way a starving man eyes a feast.

“heheheh…y’know, that chick was just tryin’ to flirt her way outta payin’ for an oil change. never thought her dumb scam would get me into bed with a sweet thing like you.”

You laugh a little. “Sans, we’ve been dating for three years?”

He grinned at you with delight. “yeah…i gotta be the luckiest fucker on the planet.”

You blush…but hell if you can’t stop smiling.

**Notes for the Chapter:**

> ....I wanted to let UF!Sans be a top for once and then feelings and something resembling a plot happened. Whoops?
> 
> Might revisit this one later on as a full standalone, I think I like it.


	17. Surprise (SF!Sans/Reader, Collaring)

**Notes for the Chapter:**

>  **Day 17:** ~~Masturbation~~ | ~~Seduction~~ | _Collaring_ | ~~Orgasm Denial~~
> 
>  **Pairing:** SF!Sans/Reader
> 
>  **Additional Kinks:** None

You got the idea when you’d asked Papyrus about his.

You’d seen them around a lot since monsters surfaced, plenty of monsters wore them, but you’d just sort of assumed it was a fashion trend and never really wondered about it beyond that.

At least, you didn’t, until you’d been taken as a monster’s lover.

So you’d asked Papyrus.

“yeah, yeah, it’s a… it’s a culture thing, i guess,” he answered you carelessly, not even looking up from his tablet. “makes a statement.”

You’d looked at the simple black leather collar around his neck and the shiny gold bone-shaped tag that dangled from it.

“So…what statement is yours making?”

“m’under my brother’s protection.” He tapped at his tag, making it twist a little. It was blank. “Sans is tough, everybody knows who he is so he didn’t even have to put his name.”

“But names are normal? For anybody else?”

“uh-huh. but y’know, only two skeleton monsters Underground, bone-tag’s gotta mean ‘Captain Sans Serif of the Royal Guard,’ and ‘this guy works for Sans, you fuck with him, you’re fuckin’ with Sans, proceed with caution.’”

“Huh. So people didn’t mess with you as much?”

“sure they did,” Papyrus had shrugged. “just didn’t usually live a lot longer after. was a little more of a deterrent that way.”

You had weighed your words, trying to figure out how to ask what you wanted to know without sounding insensitive or oversexed…

…but then you remembered you were talking to Papyrus.

“So it’s _not_ a kink thing?”

Papyrus snorted. “shit, no.” But then he added, “can be sometimes, with couples and stuff. depends on the kind of collar.”

You had him lay it all out for you.

Apparently plain leather with no frills was for working relationships—your boss might give you a collar, or if you had a tough friend who was willing to protect you, you might finagle one out of them.

More…involuntary…relationships used metal collars, literal shackles with a visible padlock to show that this person wasn’t acting of their own free will. They were in servitude to somebody stronger and meaner than them and the only way to get them out of it was to get that person out of the way.

And then there were lovers’ collars.

They tended to be more ornate, more delicate—sometimes fine chains, sometimes ribbon or lace, but _always_ worn by choice and always with a soul-shape on it somewhere, the color of their partner’s magic.

Mostly, it was the submissive partner who wore them, but it was something of an open secret that the dominant collar-mate would wear one that complemented it, just out of sight so it wasn’t obvious.

Armed with your new knowledge you planned your ambush with as much cunning and finesse as the skeleton you meant to catch, acting quickly, of course.

You wanted to have it ready in time for Sans’ birthday.

You were excited as a kid in a candy store when he finally got home after a long day at work on the day of, giving you a tired, shark-toothed grin as you greeted him.

“Happy birthday,” you said warmly, pressing a kiss to his cheek. “I have a surprise for you.”

Sans just huffed out a laugh. “UNLIKELY, BUT IT’S VERY CUTE OF YOU TO TRY.”

You put on an only slightly exaggerated pout. “You _still_ don’t think I can surprise you?”

“ _NO ONE_ SURPRISES ME,” he told you, leaning against the furniture with his arms folded, trying to affect maximum-cool-badass-ness. “IT WAS A GOOD EFFORT, YOU SHOULD BE PROUD OF YOURSELF FOR THE ATTEMPT, BUT I KNOW ALL ABOUT YOUR GIFT ALREADY.”

“Oh, do you?”

“OF COURSE! THE ORDER CONFIRMATION EMAIL WAS SENT TO OUR JOINT ACCOUNT,” he pointed out. “YOU DELETED IT QUITE QUICKLY, BUT NOT QUICKLY ENOUGH, I’M AFRAID!”

You frowned. “Aww, you saw it?”

Sans patted you on the hand, a little condescendingly but you knew it was kindly meant, so you let it go.

(That, and you were already thinking about how great it was going to be to see the look on his face…)

“I DON’T NEED TO BE SURPRISED TO BE ABLE TO APPRECIATE A WHOLE CASE OF IMPORTED REDS,” he told you, reassuringly. “IT’S A VERY THOUGHTFUL GIFT AND WE’RE GOING TO HAVE SEVERAL LOVELY EVENINGS ENJOYING IT. PLEASE DON’T BEAT YOURSELF UP TOO MUCH JUST BECAUSE YOU WEREN’T ABLE TO CATCH ME UNAWARE! NO ONE GETS THE DROP ON THE MALEVOLENT SA—”

With perfect timing, you set the jewelry box on the table with a gentle ‘tmp’ sound.

Sans’ jaw audibly clicked shut.

Yours was aching with the strain of your grin.

You watched him stare daggers at the little box, eye-sockets narrowed. You could practically see the mathematical equations floating around his skull as he retroactively put together what the hell had just happened and you wanted to laugh…

But you managed to keep quiet.

“……A DECOY,” he realized. “YOU _WANTED_ ME TO SEE THAT EMAIL.”

You shrugged. “The wine is your _other_ gift,” you told him. “This one, I paid for in cash.”

“YOU SLY _FOX_ , I CAN’T BELIEVE YOU ACTUALLY PULLED THIS OFF…”

You nudged the box a little closer to him, trying to break him out of his stunned stupor. “I didn’t pull it off just for you to not open it, go on.”

Sans took the box in his claws and opened it, sockets going wide at what was inside.

The custom black velvet choker you’d commissioned, just the right size to snugly fit around cervical vertebrae, with a charm in the middle in the shape of a heart and crossbones. It was the color of your soul, as Sans had shown it to you, with your name embroidered along the inside in the same shade.

“Do you like it?” you wondered hopefully. “I have one for me, too, but I thought…I thought you should put that one on me. And yours should fit under your scarf without being obvious, I tried to make sure.”

Sans was quiet for a long, long moment…

And then the exact opposite.

“OH MY GOD,” he exclaimed, “I AM _SO_ ANGRY RIGHT NOW?! YOU COMPLETELY BESTED ME! I DIDN’T SEE THIS COMING FOR A SECOND, YOU SURPRISED ME _AND_ YOU GOT ME A COLLAR FIRST?! UNTHINKABLE! I CANNOT BELIEVE…!”

You reached out for the box, to…maybe take it back?

But Sans immediately pulled it closer to his chest, defensively. “NO, IT’S MINE, I’M GOING TO WEAR IT _FOREVER_ , I’VE NEVER _BEEN_ SO IN LOVE WITH YOU! STARS ABOVE, GET OVER HERE SO I CAN KISS YOU!”

You laughed, but…well…your collar-mate was calling you.

You went straight into his waiting arms.

**Notes for the Chapter:**

> Finally, a chance to try out my SF!Sans!
> 
> Very minimal on the kink for this chapter, but I actually headcanon SF!Sans to have some very intense kinks and wasn't quite ready to leap right into the deep end of the kink-pool with him before I'd even given him a test-run, so here's some fluff and world-building instead. I guess? ¯\\_(ツ)_/¯
> 
> And for anybody who didn't read Chapter 11 for any reason, here's the quick and dirty guide to the SF of my headcanons based on the three most popular SF AUs: aesthetics of SF Purple/SF Gold, personalities of SF Gold/SF Red.
> 
>  **BELATED POST-SCRIPT:** I think I have to dedicate this particular chapter to [luluwrites](https://archiveofourown.org/users/luluwrites/pseuds/lulu-writes), who has a fantastic interpretation of SF!Sans without which I never would've discovered any kind of passion for the character! Thank you for coming up with such a cool take on the guy, you're an inspiration! :D


	18. Stamina (UT!Papyrus/Reader, Fucking Machine)

**Notes for the Chapter:**

>  **Day 18:** _Fucking Machine_ | ~~Latex~~ | ~~Role Reversal~~ | ~~Xenophilia~~
> 
>  **Pairing:** UT!Papyrus/Reader
> 
>  **Additional Kinks:** Overstimulation, voyeurism, slight sadism

You shut off the camera-feed and stand up.

You’ve been watching for an hour and you’re feeling a little stiff, a little bored. You think it’s time to go see it in person.

A delightful chorus of sounds greet you the moment you open the door: panting breaths, choked-off moans, rattling bones, and of course, the steady pneumatic rhythm of your machine.

Papyrus looks even _more_ wrecked up close. He’s drenched in sweat and flushing so hard he practically lights up the room, his eye-sockets and his fists clenched tightly while he just lies there, trembling.

The cute little pussy he’d made at your request looks incredible speared open around the thick rubber cock pounding it steadily, tirelessly as only a machine could.

As tireless as _Papyrus_ always seemed to be…but you think you’re wearing him down.

Your sharp, attentive skeleton hadn’t even noticed you walk in.

“Hey there, handsome,” you coyly announce. “How are you holding up?”

Papyrus’ whole body jolts when you speak, sockets shooting open and focusing on you. He didn’t have eyes for you to be sure, but you still feel like his gaze is a little hazy.

“FINE!” he exclaims quickly, _far_ too quickly. “EVERYTHING IS… I’M STILL GOING STRONG!”

You smile. “Good. Not getting tired?”

You really do admire Papyrus’ ability to put on such a bold, proud face while he was being fucked into a puddle.

“OF COURSE NOT! MY STAMINA IS LEGEND! I CAN…I CAN GO ALL NIGHT, IF YOU’D LIKE!”

You decide to do him a kindness and not hold him to that…

…but you’re not a kind _person._ Not right now.

You get closer, kneeling down beside his hip.

“That’s great. You’re doing so well for me,” you say. “How about a reward?”

Papyrus’ jaw opens, but uncertainty flashes across his skull and seems to hold his tongue.

It wasn’t a ‘no,’ though, and Papyrus knows his safe-word.

Your eyes settle on the glowing cunt between his legs, getting steadily _wrecked_ by the dildo it’s stretched around, moving in and out and in and out…

The swollen bud of his clit looks to be sorely in need of some attention to you.

You reach out, swiping your thumb along his sopping folds for more wetness before settling firmly atop his clit and starting to _rub._

“NNGH!” Papyrus claps a hand over his mouth. His whole body is rigid, completely locked up as you assault his oversensitized little pussy with more stimulation than he could possibly handle right now…

Yet somehow, he does, bucking reflexively with a gush of fluid that drenches your fingers and makes the slide of the toy still fucking his body even smoother.

You’re so _proud_ of him.

When he weakly flops back down, more limp than you thought a skeleton could possibly be, you ask him. “How many times have you come already? Including that one?”

Papyrus doesn’t even open his eye-sockets to answer you. “F…FOUR… FOUR TIMES…”

“How many more do you think you have in you?”

For the first time since you started, you hear hesitance in his voice. “I…I DON’T KNOW.”

You smirk and lean over, pressing a kiss to his cheek.

“Why don’t we find out?” you cheerily propose. “How does another hour sound?”

You feel a feral sort of delight welling up in you when Papyrus’ expression drops. In that one brief moment, he looks nervous, uncertain, _intimidated_ at the thought of another hour of _this_ …

But then his infamous bravado kicks in and he’s grinning up at you, a little wobbly but so unmistakably _Papyrus._

“IT…SOUNDS GREAT!” he boldly declares. “ONLY ONE HOUR? THAT…THAT’S NNNNOTHING…! I C-CAN HANDLE IT! THE GUH…THE GREAT PAPYRUS CAN HANDLE ANYTHING!”

“If you insist…” You stood, stroking your fingers affectionately along the damp curve of his skull. “If you need to call it quits, I’ll be watching.”

You turned to leave and from behind you, you heard him promise, “I WON’T!”

You also heard the shaky little whimper he tried to choke back as you shut the door.

You wonder how long it’ll be until he really does need to tap out, and how much longer he’ll last past that when his ego actually _lets_ him tap out.

But you meant what you said: you’d be watching, so you knew you’d see it the moment he really, truly needed to stop.

You’d see _everything._

You started up the camera-feed again and let your hand fall down between your legs to the dulcet tones of the sexiest endurance test you’d ever seen.

**Notes for the Chapter:**

> Oh Papyrus, biting off more than he can chew... >:3
> 
>  
> 
> ~~For anyone concerned, though, the reader is a good dom, he'll be hydrated and aftercare'd within an inch of his life after this. He may have to take a _nap,_ the horror, but he doesn't call himself The Great Papyrus for nothing! ;D~~


	19. Revenge (UF!Papyrus/Reader, Public)

**Notes for the Chapter:**

>  **Day 19:** _Public_ | ~~Formal Wear~~ | ~~Straitjacket~~ | ~~Cock-Warming~~
> 
>  **Pairing:** UF!Papyrus/Reader
> 
>  **Additional Kinks:** Exhibitionism (no actual discovery), more slight sadism

Papyrus felt an adrenal thrill flare up in his soul when you undid his belt and pushed your cruel fingers into his pants.

He refused to admit the feeling had anything to do with fear.

“DON’T!” he exclaimed, only to immediately curl his claws over his mouth.

 _Curse_ his prominent and commanding voice!

He’d never been any good at that weak and cowardly thing people called ‘whispering,’ and why should he have bothered to learn it? A powerful skeleton like himself should always be bold and forceful, in all things!

He tried not to think about how very _un_ forceful he’d sounded just now, hoping against hope that you wouldn’t draw attention to it.

By the wicked little smirk on your attractive human lips, he knew he’d have no such luck.

“Don’t what?” you wondered teasingly, _knowing_ he wouldn’t be able to say it again, not with his pride on the line.

You took out his cock and the ruby-red glow illuminated the cluttered little supply closet you’d dragged him into. Papyrus couldn’t help but be reminded of where you _were,_ of all the _people_ milling about just outside, and _you_ …!

You were stroking his dick like you didn’t even notice, like you didn’t _care_ who could hear or worse, stumble upon you in such a compromised position at literally any moment.

Papyrus couldn’t _believe_ your gall.

“You look nervous, tiger,” you cooed at him, reaching up with your free hand to pet at his sternum. “What’s the matter? You getting shy on me?”

Ridiculous! Utter nonsense!

“I—!”

You shushed him and he felt his cheekbones heat with magic.

“Careful, Papy, careful, you don’t wanna be too _loud,_ do you?” Your smirk rode the edge of malicious, downright _evil_ and it was so…

_Hot._

Papyrus knew for one brief moment that he was head-over-heels in love with you.

But you didn’t let him have the room to process it, or any room at all as you pressed yourself enticingly against his body, planting slow kisses along his jaw as you kept right on _fondling_ him.

In his bedroom, or even just in his own _house,_ it would be a turn-on, but here, of all places, it just made him unbearably _tense._

 _And_ so turned-on he could hardly see straight.

“You didn’t seem so nervous when you did this to _me,_ y’know…”

………

_OH, STARS, NO._

“Yeah, I remember that,” you mused, your mouth falling to his vertebrae and speaking against them in a low, seductive murmur. “We were out then, too, weren’t we? Where was that…?”

Papyrus swallowed hard. He remembered, but…perhaps discretion was the better part of valor in…just this one instance…

“Oh, that’s right… We were on the _bus._ ”

You squeezed his dick, just the right side of painful, and Papyrus shoved his hand between his teeth, trying to muffle the groan that bubbled up from his chest.

“I was _so_ worried we were gonna get caught,” you laughed. “I just kept waiting for somebody I knew to get on at every stop, thinking about how _embarrassing_ it would be to be caught with my boyfriend’s hand in my pants, magicking me into coming _all_ over myself in front of _everybody_ …”

Papyrus shuddered _hard._

Your hand just kept pumping him torturously slowly and he was getting more and more overwhelmed. When you reached under his shirt and started dancing your fingers all along his spine, he couldn’t help but let out a sound that…definitely, could not _possibly_ have been a whimper.

“I thought it would be fun to give you a turn.” Your eyes were bright with sinful glee. You were _enjoying_ this. “I thought I’d be nice and do it somewhere _almost_ private, so you wouldn’t get as embarrassed as I was.”

The sort of ‘almost private’ that was a supply closet a mere _yard_ from the main hall that was hosting the Annual Peace Gala for Monster-Human Relations. The one that Asgore himself was scheduled to speak at, with Undyne as his personal guard.

The one that Papyrus was meant to be coordinating security for _any minute now._

He’d taken a devil for his datemate. The most vindictive, cruel, and _irresistible_ human in the world.

You pulled back from him, fixing him with a teasing look. “Guess turnabout isn’t fair play, huh?”

But then you were dropping to your knees, so fast you nearly gave him whiplash.

“Don’t worry,” you assured him, “I know you’re gonna need some time to get presentable again after getting all mussed up in a closet where _anybody_ could just walk in and see you like this, so I’ll be quick. _You_ just try to be _quiet,_ okay?”

You didn’t wait for an answer and soon Papyrus was moaning through his fingers and praying that the rattling of his bones only sounded so loud to _him._

He was _going_ to get you back for this!

Somehow…

Maybe when you _didn’t_ have him on the precipice of orgasm with his soul about to hammer its way out of his ribs, and he could actually put two thoughts together…

…………

You were going to be safe for quite awhile.

 _Damn_ you.

**Notes for the Chapter:**

> I hereby dedicate this chapter to the delightful [MsMK](https://archiveofourown.org/users/MsMK/pseuds/MsMK), who introduced me to the beautiful concept that is Bottom Bitch UF!Papyrus. Thank you for everything and may the fates smile upon you for this amazing gift to the world.


	20. Lazy (UT!Sans/Reader, Hot-Dogging)

**Notes for the Chapter:**

>  **Day 20:** ~~Urophagia~~ | _Hot-Dogging_ | ~~Emeto~~ | ~~Dirty talk~~
> 
>  **Pairing:** UT!Sans/Reader
> 
>  **Additional Kinks:** Distracted sex, humor

“hey. m’horny.”

You didn’t even look up from your phone. “Hi, Horny, I’m dad.”

“i love you,” Sans said.

He let his eye-lights rove over your body, stretched out along his bed on your belly in the comfiest sweats you owned. You hadn’t showered yet and your hair was a disaster. The hem of your shirt had long ago come completely undone and there was a stain on the butt of your pants from where you’d once sat in some spilled salsa.

You were so _hot._

And to his heartfelt declaration, you responded, “Neat.”

“okay, i _really_ love you, but seriously, i’m horny.”

You just kept on screwing around on your phone. “I don’t know what to tell you, man, I don’t wanna move right now, so…”

“i get it, i get it already, you’re my soulmate.” Sans crawled closer on the mattress, giving you a little nuzzle between the shoulder blades. “you care if i just go for it?”

From here, he could see your screen. Looked like tetris.

“As long as I don’t have to get up,” you said, “you can do _whatever_ you want.”

Sans grinned, struck by a powerful wave of mingled lust and love.

And with granted permission, he climbed on top of you and tugged your pants and underwear down just below the curve of your ass.

“god, babe, i fuckin’ love your ass,” he told you, fondly, while _giving_ it a little fondle.

“Thanks, I’m very attached to it.”

Stars _above_ , you were incredible, his dick was so _hard_ right now.

Sans pulled it out and settled it between your cheeks. If you didn’t wanna get up, you probably didn’t want to sit through a lot of prep-work either, and that contained one of Sans’ least favorite words in the world, anyway: ‘work.’

So, no penetration, he was fine with it. Plenty of warm, delicious friction in dry-humping and he didn’t even have to go find the lube for that.

He started rutting against your ass. The color contrast of his magic and your flesh was one of his favorite things to look at, so he did, grabbing a soft cheek in each hand and squeezing while he fucked between them.

Sans only looked up when your phone started to make noise, crashes and laughter and groans of pain.

Holy shit, you were watching a fail compilation on YouTube, you really _were_ the perfect human.

He freed a hand so he could reach forward and stroke your messy hair a little bit. He wanted to show you how much he appreciated you.

“Oh, that feels nice,” you said. “Keep doing that.”

“oh yeah, talk dirty to me, baby…”

Of course, he had to stop petting your hair eventually. He needed that extra friction down around his dick if he ever wanted to come so he grabbed at your ass again and pressed you tighter around him.

You felt so good, _way_ better than he’d thought considering he’d actually been inside you and that had been _fantastic._ This didn’t quite top that, but it was pretty damn incredible for the barest amount of effort he was putting in.

Sans was actually close already, right on the verge of coming, he just needed a little extra something, _anything_ to push him over that last little bit…

“Y’know, they call this ‘hot-dogging.’”

“huh?”

“Look down.”

Sans did and saw where his cock was pressed between your cheeks, like a…

Oh god, like a big blue _hot-dog in a bun…!_

 __“__ heheheheh—nngh…!”

You smiled to yourself as you felt a hot spurt of come land right in the middle of your back, no doubt staining the hell out of your shirt.

“You’re washing that out.”

Sans was panting as he flopped back onto the bed beside you, still laughing. “heheheheheh, no, i’m not…”

“Yeah, no, you’re not,” you agreed. “Worth a shot.”

The shirt was already beyond saving anyway, what was one magic blue come-stain?

“worth a _money_ -shot?”

You laughed. “Can’t believe you didn’t know it was called that,” you said as an afterthought. “Mister ‘Dog Tycoon himself…”

“hey, i might’ve been a little distracted by your rockin’ _buns_.”

“Gluten-free and _bread_ y for anything. Hope it’s quality meat you’re stuffing in ‘em.”

Sans snickered. “oh yeah, the finest skeleton-sausage you’ve ever seen, babe.”

You gave him a side-eye. “Seems like a dubious source. You don’t look up-to-code with industry hygiene standards.”

“hey, i ain’t the one with jizz on my shirt.”

“…Hmm, touché.”

Sans laughs as you go back to your phone, as casual as can be.

He really is _so_ in love with you.

**Notes for the Chapter:**

> UT!Sans is a nasty slob-gremlin, that's just canon, sorry. ¯\\_(ツ)_/¯


	21. Delicious (SF!Papyrus/Reader, Food Play)

**Notes for the Chapter:**

>  **Day 21:** ~~Bukakke~~ | _Food play_ | ~~Suspension~~ | ~~Branding~~
> 
>  **Pairing:** SF!Papyrus/Reader
> 
>  **Additional Kinks:** None

You’d never, in your life, met anyone with a sweet-tooth like Papyrus.

The amount of sugar-packets he emptied into his morning coffee (to say nothing of his afternoon coffee, or his ‘fuck it, i ain’t sleepin’ tonight anyway’ coffee) was positively insane and he had enough candy stashes around the house that not even his _brother_ could find them all—and Sans was probably the most meticulous person in the _world._

You’d actually asked once if Papyrus had gotten one of his fangs replaced with that gleaming gold replica because he just ate too many sweets and got a cavity.

He’d laughed and told you it had just gotten knocked out in a scrap when he was younger and worse at dodging, but Sans had cut in with a different story.

“IT ONLY FELL OUT SO EASILY BECAUSE YOU NEVER BRUSHED YOUR DAMN TEETH!”

“if that was why, how come all my other teeth are fine?”

“IT SCARED YOU STRAIGHT AND YOU REDISCOVERED TOOTHPASTE TO KEEP YOUR OTHER FANGS IN YOUR SKULL AFTER YOUR _BRUSH_ WITH TOOTHLESSNESS.”

Papyrus had groaned. “oof, that was a bad one.”

“ _YOU’RE_ A BAD ONE!” Sans had snapped back. “AT BEING RESPONSIBLE!”

“shit, got me again, bro.”

Shamefully, you weren’t entirely sure who to believe.

But in any case, you were the furthest thing from surprised when Papyrus asked to incorporate a certain…element…into your sex lives.

Considering it was the very first thing he actually _asked_ for you to do in bed, instead of just giving you the usual ‘whatever you want, angel,’ you were happy to oblige.

You watch his dusky purple tongue trail slowly, sensually up along the skin of your inner thigh. Papyrus’ breathing had already gone heavy, _intent,_ and he hadn’t even gotten his pants off yet.

“Is it that good?” you wonder, a little amused. “You like this that much?”

Papyrus just grinned up at you, licking at his teeth. “dunno what tastes better,” he admits, “you or the chocolate…”

You have half a mind to be offended…but you’d taken a taste yourself before you started drizzling it all over yourself—it was _very_ good chocolate.

“Guess you’ll just have to keep tasting then,” you say. “Until you can make a decision.”

You take the chocolate sauce, holding it just over your belly, and start to pour. The thick, dark syrup hits your skin and gravity takes its course, pulling it to drip down, down, down and leaving the tastiest line from your navel to your groin.

You think you can actually see Papyrus start to _drool._

He all but lunges for you, holding you still with his clawed hands while he rudely slurps the confection from your body. His enticingly _long_ tongue writhing passionately against you is an incredible sensation, but it only gets better when he gets between your legs.

You think he’s had more than enough free rein by now.

You grab him by the back of his skull and _hold_ him there, a wordless command to keep going and by his fervent licking, you think it’s one he’s happy to obey.

“you,” he eventually mutters, breathless and muffled against your body. “you, it’s you, so fuckin’ _good_ …”

You stroke his skull and grin.

Papyrus is so _sweet…_

**Notes for the Chapter:**

> I think I headcanon all the Papyri as having very serious sweet-tooths. Some hide it better than others. Some don't hide it at all. Pretty easy to guess which of those two my SF!Papyrus falls into, I think. XD
> 
>  
> 
> ~~Holy shit, I actually caught up? Wild, probably gonna fall behind again soon, but what a feeling of accomplishment for the next... *checks clock* hour and a half!~~


	22. Stress Relief (US!Papyrus/Reader, Hand-Jobs)

**Notes for the Chapter:**

>  **Day 22:** ~~Impact Play~~ | ~~Cuckolding~~ | _Hand-jobs_ | ~~Threesome (or more)~~
> 
>  **Pairing:** US!Papyrus/Reader
> 
>  **Additional Kinks:** Come licking, authoritativeness kink, clothed sex

You’re watching TV—well, that thing where it’s on and you’re looking at it but not really processing anything you’re seeing, at least—when you catch a flash of orange out of the corner of your eye.

You instinctively turn and jump to see Papyrus suddenly sitting next to you.

“Shit, Paps, don’t _do_ that,” you chide with a hand over your chest. “Didn’t we talk about this? Fight or flight? If I had any survival instincts beyond that of a goldfish, I could’ve taken a swing at you just now!”

Papyrus…didn’t answer you.

You took a closer look at him. The expression on his skull was blank, probably much like your own had been a minute ago—staring dead-ahead but not really seeing a thing. There were dark circles beneath his eye-sockets and a clear line of tension in his jaw and shoulders.

“……Papyrus? You okay?”

You jump again when he just flops over onto you like a ragdoll, his head facedown in your lap.

“Not even gonna buy me a drink first?”

“…eh.”

Oh wow. He usually _loved_ flirting. You teed it up for him and he wouldn’t even swing?

“Bad day, baby?” you wonder a little more gently.

“i love my job,” came the muffled, monotone reply. “the enrichment of all generations, past and future, is my passion.”

Your eyebrows shoot up.

“Yikes,” you mutter, “ _that_ bad?”

Papyrus sighs and rolls over, looking up at you beseechingly. “why are people so stupid? why does nobody know what a library is?”

“Maybe that’s why they’re there,” you suggest. “They’re stupid and they need to learn.”

“no, they’re there to yell at me for not sellin’ them books ‘cause i’m ‘slow’ or ‘discriminatory’ or ‘don’t understand the meaning of good customer service.’ couldn’t have anything to do with the fact that i _don’t work at a bookstore,_ no, that’d make _sense_ or somethin’…”

Papyrus scrubs a hand over his face and you reach for him, stroking your fingers along his skull and his sternum. You feel him relax a little at your touch and it makes you smile.

“Remember the good days,” you encourage. “The ones where you…sign little kids up for their first library card, or…talk to other nerds for way too long while you check their books out.”

Papyrus squints at you through his fingers. “you callin’ me a nerd, hon?”

“You _are_ a nerd, jellybean,” you tease…but you saw him smiling, so you knew you hadn’t bruised his ego too badly.

“mmm, yeah, okay. i guess.”

He ‘guessed.’ You couldn’t help but roll your eyes: the man had three bookshelves in his room, six or seven more scattered throughout the house, and it _still_ somehow wasn’t enough to keep the damn things off and out of every other conceivable location…and some that were _in_ conceivable.

You still had no idea how he’d managed to wedge that high fantasy romance novel in his ribcage and keep it from falling out all day. His books were something that made him happy, though, and _you_ were happy to support that.

Of course, you had your own way of making Papyrus happy, and not _only_ by being his loving, supportive datemate.

You let the hand you had on his sternum drift even further south, sneaking beneath his waistband. Your fingers sought his pubic symphysis, the little dip in the front of his pelvis, and you started to rub.

Papyrus inhales sharply, half-sitting up.

“hey, uh…that’s…you know you don’t have to…to…”

You pull your hand back and use it to shut his jaw for him.

“I don’t have to,” you agree. “I want to. You had a rough day and I want to make it a little better. I’m going to reach back down and when I do, there’s going to be a dick in my hand. Okay?”

Papyrus shivers. “okay.”

You knew he liked it when you got firm with him sometimes. _He_ was pretty firm, too, when you took him in hand again, his magic humming gently beneath your touch.

“Just a little stress relief,” you said, feeling his cock grow slick to ease the glide of your fingers along its length. “You earned this. I’ll make it good for you.”

That was a promise you knew you could keep. You kept your grip strong, but not tight, pumping him too slow to get him off quickly, but not slow enough that it was teasing; just the right pace for him to really take his time and _enjoy_ it.

From the looks of it, he was.

Papyrus was flushed in your lap, breathing a little heavier as he started fucking up into your hand. His lidded eye-sockets were fixed firmly on you and you think if he had eye-lights, they’d be heart-shaped right about now.

The feeling was mutual and you stroked his skull just as tenderly as you stroked his dick.

“Love you, Papy,” you gently reminded him.

His cock twitched in your hand, getting wetter and stickier as he unceremoniously came all over your fingers.

“nngh, fuck, shit…!” He panted for a moment before going completely limp, practically melting over your lap. “…love you, too…”

You grinned happily, even as you pulled your hand out of his shorts to see it completely coated in his magic.

 _Gross,_ you think fondly.

Papyrus eventually notices it, too. “oh, sorry.”

“If you’re sorry, do you wanna move so I can get a paper towel?” you wonder.

As you suspected, Papyrus grimaces. “mmm, nah, m’good here. just wipe it on my hoodie.”

“You’re disgusting,” you laugh. “I want you to know that you _made_ me do this.”

“do what?”

You don’t leave him in suspense for long. You lift your come-slick fingers to your mouth and clean them off with your tongue.

One by one.

“…oh _shit_ …”

You know you have Papyrus’ rapt attention, especially when he actually sits up and frees your lap, catching you by the shoulders.

“i’m up, i’m up,” he murmurs excitedly against your lips. “y’happy now?”

Yes. Yes, you were.

**Notes for the Chapter:**

> Fluff and hand-jobs, who'da thunk? ¯\\_(ツ)_/¯
> 
> I have [a tumblr](https://popatochisssp.tumblr.com/) now! Come say hi, if you want! :D


	23. Big (HT!Sans/Reader, Size Difference)

**Notes for the Chapter:**

>  **Day 23:** ~~Scars~~ | ~~Master/Slave~~ | ~~Shibari~~ | _Size Difference_
> 
>  **Pairing:** HT!Sans/Reader
> 
>  **Additional Kinks:** Soulmates, puns

You’d always had a thing for big guys.

It had been the subject of countless jokes and ribbing from friends since you’d hit puberty and your preferences had become clear. Anytime somebody tall or broad or thick walked past, the response was the same, an elbow to your arm and some snickering.

‘Hey, look,’ they’d tell you, ‘it’s your next boyfriend!’

Then the monsters had surfaced, massive inhuman creatures coming forth from the depths of the earth, fresh out of years upon years of imprisonment and suffering… and the first thing you heard about it from a friend was how you should be happy: you were about to meet your soulmate.

You had chastised them for saying something like that, thinking it was pretty insensitive to make jokes when these poor people were just crawling out of a near-literal hell.

…but they hadn’t exactly been wrong.

You’d met Sans just a few weeks later and well…apparently, soulmates were an actual thing for monsters.

And you were his.

You didn’t protest when the towering, broad-shouldered skeleton with a glowing red eye and a jagged hole in his skull had come right up to you and grabbed you into a hug.

You were a little distracted by the way your body was responding to the fact that you were eye-level with his sternum and his huge hand encompassed basically your entire skull to even consider protesting at the time.

Thankfully for the both of you, Sans’ brother had been there, too.

Twice as tall as you but infinitely more spindly than Sans, Papyrus had been able to explain the concept of soulmates to you while you peeked up at him from under Sans’ arm. He’d suggested that you might consider going on a date with his brother, if that was something you were open to?

You were. You were _very_ open to a date, and then another, and another, and by now, Sans is the longest relationship you’ve ever had and you wouldn’t change a thing.

You even have a feeling that this interest in the size mismatch between you goes both ways. You’d seen some signs, picked up on hints and little reactions and you’ve started thinking that Sans might like how small you are compared to him as much as you like how big he is…

You decide it’s time to find out.

You find Sans napping in a beanbag chair and climb up into it with him. He stirs a little when you settle yourself in his lap.

“Sorry,” you say, not feeling very sorry at all. “Did I wake you?”

Sans looks down at you with droopy eye-sockets. “little bit,” he admits. “yer fine…”

“Just missed you.” And that bit’s true, so you lean up, bracing your hands on his chest so you can get up high enough to kiss him. He sleepily nuzzles you back a little and you grin against his teeth. “Feels like climbing a tree.”

He doesn’t seem to follow right away. “huh?”

“Trying to kiss you,” you explain. “I have to _climb_ you just to get up far enough to reach.”

“oh. heheh…” He’s blushing a little, but you see his permanent smile widening. “sorry for your _pine_ and suffering. dunno how to re _leaf_ you of it. m’a little _stumped._ ”

Ever the jokester, your Sans, even when you’re literally on top of him.

You still laugh, but you decide to try a little harder.

You slip your hand under his shirt and curl your fingers around one of his upper ribs. It’s incredibly thick and very sturdy, and when you tug on it, you watch Sans’ eye-light shrink a little.

“It’s all good,” you tell him playfully. “You’ve got a built-in ladder for me.”

“eheheheheh…that’s…”

You grab at one of his hands and feel him instinctively wrap it around yours. His huge bony phalanges envelop your fingers completely and you don’t think words exist to explain how much you love that.

“Y’know it actually hurts my hips a little?” You gesture and watch his red eye fall to where your legs are splayed over his lap. “Holding my legs open so _wide_ just to _straddle_ you…”

Sans is sweating a little…but the heated intrigue on his face is plain as day. He’s caught your drift and he’s _liking_ it.

When he lets go of your hand and reaches up, settling those big mitts of his on your waist and staring intently at the way his thumbs nearly touch over your belly, you _know_ you were right.

This turns him on as much as it turns you on.

And it turns you on _a lot._

“You wanna take me to bed, big boy?” you wonder coyly. “Don’t really want to fuck in a beanbag.”

You chuckle as Sans stands up, scooping you up right along with him. He’s so stupidly big and broad that all he needs to hold you up against him is one arm under your ass and it makes you shiver with delight.

“yep,” he breathes, “bed. _fuck,_ yer teeny…”

Your grin feels sharp with anticipation. “I’m not teeny,” you laughingly protest, “you’re just _huge_!”

**Notes for the Chapter:**

> What do you mean this is the same big bara sweetheart Sans from [FGTC](https://archiveofourown.org/works/15881328/)? No, it isn't.
> 
>  
> 
> ~~It is, a little bit. Just a little bit.~~
> 
>  
> 
> Hmu on my new [tumblr](https://popatochisssp.tumblr.com/) if you want to chat and whatnot!


	24. Great Taste (SF!Papyrus/Fem!Reader, Pegging)

**Notes for the Chapter:**

>  **Day 24:** _Pegging_ | ~~Leather~~ | ~~Lapdances~~ | ~~Shower/Bath~~
> 
>  **Pairing:** SF!Papyrus/Fem!Reader
> 
>  **Additional Kinks:** Emotional assurance, healthy relationships

You choke on your drink when you see the monstrous _thing_ on Papyrus’ screen.

“No,” you say immediately. “ _Fuck_ no, I don’t want that thing anywhere _near_ my nethers!”

And why would you? The hot pink cock-shaped obelisk isn’t just huge, it’s _impractically_ huge and covered in bumps that look more like _spikes._ Just looking at it makes you clench _everywhere_ and you can’t process a thought beyond _‘do not want.’_

It’s probably why you miss a crucial dimension of the toy, even as Papyrus pulls his tablet a little closer to his chest, defensively.

“…not for you,” he mutters.

“What?”

“………not for you,” he says a little louder, his cheekbones going purple. “it…i thought…”

You look a little closer at the picture and see that the dildo he’s looking at isn’t a dildo: it’s a _strap-on._

He wanted it for _him._ For you to _use_ on him because you didn’t _have_ a cock.

“never mind,” he says quickly, shutting the tablet off and shoving it away. “it was dumb, i don’t need…it’s fine, i’ll just—”

You cut off his embarrassed verbal panicking by wrapping your arms around his shoulders. You hug him, squeezing tightly as you press a kiss to his glowing face and reach out to pick the tablet back up.

Really, you should’ve known he was looking for himself. Papyrus’ eye-sockets were always bigger than his metaphorical stomach.

“Too big,” you say, turning the tablet back on and backing out of the detail page for the Neon Pink Torture Device. “Not happening.”

You feel Papyrus squirm a little in your arms. “i know,” he mumbles weakly. “i get it, you don’t wanna—”

“Too big,” you say again, harder this time. You let him watch you go to the search settings of the website he’d been on, adjusting the size parameters and scrolling through the new results. “If we’re picking out _my_ dick, I want one that’s not going to crack your pelvis in half on the first try.”

As soon as he realizes you’re not shooting him down or shaming him for the thing he wants to do, Papyrus relaxes.

And between the two of you, you settle on something you can _both_ enjoy.

The first time you put it on is definitely a little weird.

You’re not used to having something protruding from between your legs and of course it’s a very bright, unnatural color that’s jarring to the eye.

Papyrus had favored that, though, saying it was the color of your soul, so you’d pretty much had no choice but to get it.

Well, because of that, and the modestly-sized inner-attachment for _your_ pleasure, supposedly set to sync up vibrations based on pressure signals it receives from the outer-attachment.

You were beyond excited to test _that_ out.

Papyrus looks excited, too, sprawled out on his back underneath you and practically vibrating himself. He’s formed a dusky violet pussy between his legs and he’s already so wet that it glistens in the low light of the bedroom, looking genuinely beautiful.

You straddle one of his long, long legs, bringing the other one up over your shoulder and gently nudging against his entrance. “You ready?”

“yes,” he says quickly, eagerly, and who are you to deny him?

You press forward into him and his head falls back against the pillow with a low moan. He must be tight, clenching hard around your cock because the half inside you buzzes to life with a powerful whirr and you shudder from it.

“good?” Papyrus asks, trying to sit up a little on his elbows. “is it good? do you…?”

You have the sudden thought that you like him better horizontal. And moaning.

So you make that happen, instead.

You pull your hips back and snap them forward, hilting in him in one rough motion and he shuts right up, falling flat on his back again just like you wanted. There’s a weird sort of power in getting to fuck him like this—instead of all the other ways you’ve fucked him—and you hug his femur to your chest and keep thrusting.

Papyrus groans, clawing at the bed sheets as you rut into his body, harder, faster, _deeper_ every time. You feel him fluttering around you through the toy, stuttering and delicious vibrations in your core that tighten the knot of pleasure in your abdomen with every passing second.

“Fuck, Papy, you feel so _good_ ,” you coo down at him, watching him light up with a blush and try to cover his face.

You let him do it, but only because you’d have to let go of his leg to pull his arm away and you don’t _want_ to stop fucking him, not for anything.

You think if Papyrus were a little more verbal right now, he’d tell you so too, but his long, breathless moans are music to your ears all the same.

You’re close, you’re _very_ close, and you speed up making sure Papyrus is right there with you.

“mmm, pl…please,” he stammers, struggling to focus long enough to form the words he wants. “more…!”

You give it to him. You give it to him and he practically howls as he comes _hard,_ his cunt clamping down around you and forcing you right over the same precipice in a burst of color and sensation.

“Ohh, _fuck_ …! Mmngh…”

As your orgasm fades, you pull out and unclip the strap-on’s harness, discarding it haphazardly on the bed so you can crawl up and give your skeleton a proper cuddle. His bones are sweaty, trembling a little, but you couldn’t care less.

“That was great, Papyrus,” you murmur, pressing smooches all along his jaw, his vertebrae, his clavicle. “Thanks for talking me into trying it.”

He’s still panting, trying to catch his breath, but he smiles at you sheepishly, gold tooth glinting.

“thank _you,_ ” he says. “you, uh…you picked a good one…”

Your grin is proud, probably unbearably smug. “Of course I did. I have great taste.”

And then you lean in to give Papyrus a kiss.

**Notes for the Chapter:**

> I know, I know, pegging is technically 'anal'...but if you've got a man who can shift his genitalia at will, why _not_ make use of a pussy sometimes? It's still a lady penetrating a gentleman, so that's technically accurate!
> 
> Although the way I write this fem!reader stuff is such that it doesn't even _have_ to be a lady, I try to stay vague with the pronouns so you could fit any kind of gender identity in there you want to. Fem!reader is just the quickest way for me to indicate that there's a confirmed vagina in play.
> 
> Oh well, this is the chapter that came out and I'm not changing it! Hope you enjoy anyway! ¯\\_(ツ)_/¯
> 
> My [tumblr](https://popatochisssp.tumblr.com/) is here if you want to hang out over there! :)


	25. Heel (SF!Sans/Reader, Boot Worship)

**Notes for the Chapter:**

>  **Day 25:** ~~Tickling~~ | ~~Scat~~ | _Boot Worship_ | ~~Olfactophilia (Scent)~~
> 
>  **Pairing:** SF!Sans/Reader
> 
>  **Additional Kinks:** Obedience kink, uniform kink, d/s dynamics, rank play

Sans is asleep on the couch and you resist the urge to ‘aww.’

You don’t want to bruise his ego, naturally, but there’s also the fact that he’s hyperattenuated to noise and his startle-reflex tends to be materializing a baker’s dozen of floating demon-wolf skulls that fire lasers and that’s not a fun thing for _anyone_.

Sans had been utterly mortified the one time you’d gotten caught in an unexpected crossfire and had fretted over you very sweetly, but it turned out that you had a natural talent for dodging and only ended up with a tiny fraction shaved off your HP for the trouble.

He still pampered you for the rest of the day in between very firm orders to _never_ sneak up on him again because he would hate for his ‘wildcat reflexes’ (his words) to bring you to any serious sort of harm.

Remembering that incident was really _not_ helping your desire to ‘aww.’

You definitely don’t want to startle him awake today, though. You can see from your place at the doorway that Sans is wearing his Royal Guard uniform instead of one of the expensive, fitted three-piece suits he wears to do his actuarial freelancing, which means he’s just gotten back from the Monsterkind Embassy.

He’s just spent his entire morning, afternoon, _and_ evening with Empress Toriel and General Alphys riding his coccyx and barking orders at him and the last thing you want to do is pile on anymore stress.

But…you think there _is_ something you can do, something you’ve been wanting to try for awhile ever since you first saw Sans in that sexy uniform. You feel excitement bubbling up in your chest and a playful smile overtakes your lips.

First, you lean a little heavier on the door-frame, making sure that the old wood audibly creaks.

Sans doesn’t move or open his eye-sockets, but you _know_ he’s awake now. It’s safe to approach, so you do…

…on your knees.

Sans ‘humors’ you, still feigning sleep until you curl your fingers around his ankle and femur, stroking at the smooth leather of his thigh-high boots.

“AND WHAT DO YOU THINK _YOU’RE_ DOING?”

You look up at him through your eyelashes, appropriately demure. “Welcome home, Captain,” you purr. “May I greet you properly?”

It’s obvious that Sans isn’t quite sure what you’re playing at, but _very_ interested to find out.

Anything that had you addressing him by his rank was _bound_ to be to his liking.

“YOU’RE QUITE LATE,” he sneered, checking his pocket-watch for effect. “I’VE BEEN HOME SEVENTEEN MINUTES ALREADY WITHOUT A WELCOME…BUT I _SUPPOSE_ I CAN OVERLOOK IT, JUST THIS ONCE.”

“Thank you, Captain.” You nuzzle his knee a little and he strokes your hair. “It won’t happen again…”

“IT HAD BETTER NO—……OH.”

It wasn’t often you rendered Sans speechless so you reveled in it now, even as you pressed another deep, lingering kiss to the pointed toe of his boot.

These damn _boots_ …

The subject of many a dirty, late-night fantasy for you with the polished sheen of their leather and the sharp platform heels that gave Sans a few extra inches of confidence that he wore like a king.

You’d wanted to do this for a long time and you had a feeling it showed.

“MY, MY, LOOK AT _YOU,_ ” Sans breathed above you. “SO EAGER TO SERVICE ME…”

You pulled him a little closer by his heel and kissed more fervently while he chuckled.

“YOU DIRTY HUMAN…” You didn’t look up, but you knew he was grinning, that broad predator’s smirk that was wickedly sharp and undoubtedly dangerous. “DO YOU GET OFF ON KISSING MY FEET? LICKING THE FILTH FROM MY BOOTS?”

Sans was far too meticulous for filth, and he’d been traipsing around the Embassy all day, with its gleaming marble floors so clean you could _see_ yourself in them. You didn’t taste anything on your lips but the clean, well cared for leather of his boots.

But you were happy to play along. You met his eyes, opened your mouth and dragged your tongue along the curve of his ankle, straight up his shin.

His eye-lights contracted and before you knew it he was nudging you back with his toe.

“THAT’S ENOUGH,” Sans said firmly. He snapped his fingers and pointed down, grinning excitedly. “DO THE OTHER ONE.”

You smiled and bent to attend to your task with a coy little, “Yes, Captain…”

It looked like you’d found something the both of you could have fun with.

You just hoped that meant Sans would start strutting around in these kinky boots of his more often…

**Notes for the Chapter:**

> Originally thought 'boot worship' was a little too obvious for SF!Sans, but...I couldn't/didn't want to make any of the other prompts for this day work, so here we are! I don't think it came out _as_ clichéd as I worried it would. :)
> 
> Come hmu on [my tumblr](https://popatochisssp.tumblr.com/) if you want to talk or see the nonsense I reblog over there! :D


	26. Challenge Accepted (UT!Sans/Reader, Toys)

**Notes for the Chapter:**

>  **Day 26:** ~~Lactation~~ | ~~Roleplay~~ | ~~Smiles/Laughter~~ | _Toys_
> 
>  **Pairing:** UT!Sans/Reader
> 
>  **Additional Kinks:** Exhibitionism, public sex, slight sadism

“…so this guy’s been there two hours now, his kids are gettin’ cranky ‘cause all they’re seein’ is a bunch of empty enclosures an’ nothin’ else. it’s a total nightmare, all he wanted was a happy little family outing to the zoo an’ there’s nothin’, total ghost town, until finally, _finally_ at the _very_ back of the place, they find the one exhibit with somethin’ in it.”

You watch Sans from your stool beside him at the bar. You’re not paying much attention to the joke but you’ve heard it before.

You’re the one who _told_ it to him. You know how it goes.

“it’s a dog,” Sans chuckles, like he can’t believe it. “one whole damn zoo an’ the only thing in it is one little dog!”

He sighs, taking a swig from his ketchup bottle for the dramatic pause before the punchline.

“it was a _shih tzu,_ ” he shrugs, and the entirety of Grillby’s _loses_ it around you in a raucous chorus of laughter and table-slamming.

Sans takes a lazy half-bow from where he’s sitting and shoots you the most infuriating look out of the corner of his eye-sockets, his grin unbearably smug.

 _Yes, Sans,_ you grumble in your head. _I saw: **perfect** joke delivery while sitting on a vibrator. You are a **god** among skeletons._

You’d bought the specialty panties on a whim, thinking maybe you’d wear them yourself sometime and spice things up…

…but you reconsidered that idea _very_ quickly.

Your boyfriend was an absolute _troll_ of the highest magnitude and you knew if you gave him control over a toy like that, he’d abuse it in the worst ways possible just because he’d think it was funny. Turning it on or up at exactly the worst moments, in front of the worst people possible, giving you calls that were just _way_ too close for comfort…

Sans would _say_ he had it all under control and would never embarrass you in public, but he loved to tease you and you didn’t quite trust him to know exactly where your ‘embarrassment’ line was since he himself was a man completely without shame.

Sans had only shrugged and agreed, “yeah, fair,” when you’d explained as much to him.

That was why _he_ was wearing the panties now, hidden beneath his basketball shorts.

His poker-face was the stuff of legend, nearly impossible to fluster, and hey, even if somebody caught the two of you at it…?

Shameless, he didn’t _care._

He’d _picked_ Grillby’s as the place to play this game, with all his barfly pals who knew him by name and the elemental bartender who had utterly given up on expecting his tab to be repaid anytime in the next few decades.

You’d had the toy inside him going steadily for about twenty minutes now. A few sporadic bursts on and off earlier had done absolutely nothing to crack Sans’ veneer, not even while he was mid-sentence or hopping on or off his stool, so you’d thought slow and steady might serve you a little better.

From the brash look of amusement on Sans’ face, you know he’d disagree.

He leans over to you a little, putting an affectionate hand on your arm. “what’sa matter, babe?” he wonders. “you not feelin’ the _vibe_ in here tonight?”

Oh, this cocky _fucker,_ he was _punning_ about it.

You just smile at him, though.

“I’m fine,” you assure him. “Feeling a little _low_ energy, though, you think you could order me a cola or something?”

“yeah, sure thing.” Sans gives your cheek a little nuzzle and turns back to the bar.

Hmm…your poor skeleton. He’d let himself get just a pinch _too_ cocky.

He’d completely missed your warning.

You reach into your pocket for the remote as Sans waves Grillby over from the other end of the bar. You wait until he starts to speak before turning the knob.

“hey, grillbz, can i get another c—ghk…!”

Sans’ whole body goes rigid for a second, eye-sockets shocked wide as he suddenly white-knuckles the edge of the bar.

Grillby’s orange flames flicker a little in what you’ve come to recognize as concern, leaning forward a little bit to see if Sans needs any help.

You have to hand it to Sans, he’s a _very_ quick recovery.

He forces out a cough and gently thumps a fist at his sternum. You have enough mercy to turn the vibrator back down to ‘low’ so he can gather himself, and you hope Sans is appreciating it now.

Who knows how long your mercy is going to last?

“phew, uh, tickle in my throat,” Sans bluffs, ignoring the fact that he doesn’t have a throat and knowing nobody’s about to call him on it. “can, uh, can we get another cola over here, grillby? you can, heheheh, you can put it on my tab, the usual…”

If Grillby had eyes, you think he’d be rolling them, but he goes off to pour your order for you.

While he’s gone, you sling your arm around Sans’ shoulder, a casual and affectionate gesture that no one bats an eye at.

“What was all the _buzz_ about, Sansy?” you tease.

He doesn’t answer you, but you can see him realizing what you already know: he’s not as in-control here as he’d thought.

“I’m having a good time,” you say, trying not to smirk. “Are you having a good time?”

Sans isn’t fooled by the faux-nonchalance in your voice, his eye-lights flicking down toward the pocket where you’re still holding the little remote.

“heheh…you know it,” he laughs a little, a _slight_ nervous edge to his voice. “is, uh…is there any _remote_ chance you’re gonna take it easy on me tonight…?”

You laugh, like he’s just told you a private couples’ joke and you think he’s the funniest guy in the world.

You _do_ think that…but you also think he could do with being taken down a peg or two in this little game you’re playing.

“Oh, baby,” you chuckle, “I _am_ going easy on you.”

You lean in, pressing a kiss to his cheekbone.

As you pull back, you whisper, “That was ‘ _medium._ ’”

If skeletons could blanch, you think those words would’ve made Sans go pale. There’s some sweat beading along Sans’ skull and you…

You’re _thrilled._

Your drink arrives and Sans wordlessly passes it to you. You give him a grateful pat on the shoulder and take a sip.

You fiddle a little with the knob on the remote and wonder what’ll happen to Sans’ legendary poker-face if you switch it to ‘high.’

Hmm…maybe _you_ were a troll, too.

You shrug it off. Sans could teleport if he happened to discover a shred of embarrassment deep down in his bones and if he didn’t…

Well, he’d asked you to challenge him. It didn’t seem right _not_ to push the envelope a little.

You slowly twist the knob.

**Notes for the Chapter:**

> Oh, Sans...never get cocky around the human holding the remote. ( ͡° ͜ʖ ͡°)
> 
> [My tumblr!](https://popatochisssp.tumblr.com/)


	27. Safe (US!Sans/Reader, Against a Wall)

**Notes for the Chapter:**

>  **Day 27:** ~~Exhibitionism/Voyeurism~~ | ~~Degradation~~ | ~~Gun Play~~ | _Against a Wall_
> 
>  **Pairing:** US!Sans/Reader
> 
>  **Additional Kinks:** Overstimulation, called safe-word, aftercare

You were _exhausted._

Your skin was so slick with sweat that you think you’ve forgotten what ‘dry’ feels like. You’re so hot and sticky and _sore,_ and you’re panting hard to catch your breath, but it feels like a fruitless struggle.

Sans is panting, too, down by your shoulder. Unlike you, though, he doesn’t seem to be struggling one little bit, tirelessly rutting into you like he had been for…

Fuck. You couldn’t _remember._

Who could blame you?

It was so hard to focus on anything but _Sans_ right now; on the sturdy bones holding you aloft and flush against the wall, on the thick cock pistoning in and out of your body, on the teeth ever so gently nibbling at your neck…

Sans was your _world_ right now and that was just the way he liked it.

“YOU’RE INCREDIBLE,” he murmured against your flesh. “I LOVE YOU SO MUCH…”

You weren’t quite sure you had the breath to reply. You give him a weak little pat on the shoulder and nuzzle the side of his skull, hoping he gets the message.

Sans chuckles a little and you shiver as he speeds up, snapping his hips against you even faster and harder. His fingers dig into your hips as he comes inside you for the nth time with a little growl that would be very, very sexy…if only you weren’t so _tired_.

When he finally stills, you slump forward against him but he nudges you back against the wall so he can kiss you. You reciprocate as best you can and you allow yourself a moment of hope.

Sans was done, right? He _had_ to be done…

You groan aloud, half-sensation and half-disbelief as he slowly starts to move again.

“Are…are you for real…?” you manage to gasp out, shivering from stimulation you’re not quite ready for, not so _soon._ “Seriously? _Still_ … _?!”_

Sans smirks up at you, almost innocently and damn him, the bastard hasn’t even broken a sweat. “I TOLD YOU,” he reminds you. “I CAN GO ALL NIGHT!”

You…you can’t.

You’d wanted to, you really did, but you _can’t,_ you’re tired and sweaty and a _wreck,_ and you weren’t even sure if you’d come the last few rounds because it was all such a blur…

It was too much. You were calling it.

“Zero Kelvin,” you huff, “zero Kelvin, I’m done, _fuck_ …!”

You don’t have to say anything else: Sans knows the safe-word as well as you do.

Sans pulls out of you and swings you into a bridal carry with ease, like even after rutting against you like an animal for what had to be hours, he still had all the strength in the world.

He probably _did_.

“You’re a _machine_ ,” you grumble at him as settles you onto the bed, getting you comfy against the pillows. “You’re _impossible,_ I dunno how you do it…”

Sans seems utterly untouched by your annoyance. He just grins at you and presses a very sweet kiss to your forehead.

“THE MAGNIFICENT SANS KNOWS NO LIMITS,” he boasts. “…EXCEPT FOR THOSE OF MY VERY WONDERFUL AND ACCOMMODATING HUMAN, OF COURSE.”

……damn, you can’t even stay _annoyed_ at him.

“STAY HERE,” he tells you brightly. “I’LL GO GET YOU A DRINK AND A TOWEL. YOU’RE _VERY_ DAMP AND STICKY RIGHT NOW!”

Gee, you hadn’t noticed.

But it wasn’t like you _could_ go anywhere anytime soon, not with the way all your limbs felt like overcooked noodles, so you stayed where you were—flopped back against the pillows and catching your breath.

By the time Sans returns, holding a bottle of something neon orange and a neatly folded towel, you’re frowning and picking at the hem of a pillowcase.

“Sorry,” you mutter.

Sans tilts his head at you, even as he cracks open the drink for you and passes it over. “FOR WHAT?”

You take an awkward little sip and look down, tasting the burst of citrus and electrolytes on your tongue. “…safe-wording? I said I wanted to keep up with you and then I—”

“DON’T EVER BE SORRY FOR THAT.”

You look back up when Sans joins you on the bed, sidling right up to you. He takes the towel to your body and starts drying you off, and the smile he gives you is so…

Gentle. Loving.

 _Damn_ it, you’re head-over-heels for this skeleton.

“I LIKE PUSHING YOU, BUT I _NEVER_ WANT TO BREAK YOU. I _WANT_ YOU TO USE THE SAFE-WORD WHEN YOU’VE HAD ENOUGH. THAT’S THE WHOLE REASON WE HAVE ONE!”

You make a face. “Even when it means you don’t get to come?”

Sans snorted loudly, raising his browbones at you. You follow the gaze of his eye-lights down between your legs where he’s currently wiping…wow, a _lot_ of blue come off and out of you.

“I THINK I GOT TO COME A FAIR BIT TONIGHT,” he laughs, “AND EVEN IF I DIDN’T, YES—YOU ARE MORE IMPORTANT TO ME THAN AN ORGASM. ALWAYS.”

You look him in the eye, trying to convey the depth of feeling in your heart right now.

“Inscribe that on my wedding ring,” you tell him, only to gasp. “No, no, write it into your _vows,_ that’s better!”

Sans tries to hold back his laughter for a moment before failing miserably.

“PFFFFFT, HEHEHEHEHEH, DON’T YOU ENABLE ME,” he tries to chide you. “I’LL ACTUALLY DO IT! DON’T THINK I WON’T!”

“If you don’t, _I_ will,” you snicker.

“THIS IS WHY,” Sans says, leaning forward to press his teeth to your lips, “THIS IS WHY I’M MARRYING YOU.”

You kiss him back—difficult when you’re smiling so hard—and daydream a little about the shocked faces of all your wedding guests if either of you make good on your word.

The ceremony is going to be _beautiful._

**Notes for the Chapter:**

> US!Sans is the king of aftercare, even as he's simultaneously the king of 'oh my god, how are you still _going,_ what the fuck, where is your off-switch?!'
> 
> He never disregards a safe-word, though! None of my skeles ever would, when you're done, you're done, 'always kink safely' is rule number one!
> 
> Also...didn't go into this one intending to have Reader and US!Sans engaged, they just sort of sprung it on me. Happy nuptials to them, I guess! XD
> 
>  
> 
> [My tumblr!](https://popatochisssp.tumblr.com/)


	28. Game (SF!Sans/Reader, Humiliation *CON-NONCON*)

**Notes for the Chapter:**

>  **Day 28:** ~~Omorashi~~ | ~~Stripping/Striptease~~ | ~~Vore~~ | _Humiliation_
> 
>  **Pairing:** SF!Sans/Reader
> 
>  **Additional Kinks:** CON-NONCON, ALL CAPS ON PURPOSE FOR READER-SAFETY, bondage, derogatory words, rough stuff, all totally consensual and safe, but please mind these warnings if any of these is a kink too far for you

You took a moment to catch your breath, wiping idly at your bloody shoulder.

The wound was shallow and barely stung, just a jagged semi-circle where your new little toy had snapped at you before you’d gotten him properly secured.

Before you’d crammed a bit between those nasty shark-teeth of his.

He was still growling at you through it, yelling muffled words that were undoubtedly curses upon you and everything you’ve ever loved, but you weren’t particularly troubled by that.

 _He_ was the one all trussed up in a hog-tie on the floor and _you_ were the one standing over him victorious.

“It was a good try, sweetheart,” you coo at him, kneeling down to his level. He growls at you again, his ultraviolet eye-lights burning with impotent rage, and it makes you chuckle. “Come on now, no more of that… You got your little fight and you _lost._ You’re mine now.”

“MMRRRGH…!” he snarls, wriggling furiously against his bonds.

They hold tight, just like you knew they would.

“Oh no…you’re not still trying to get _out_ , are you?” You laugh a little bit, giving his skull a patronizing little pat that he tried to ineffectively jerk away from. “Honey…it’s _over._ You’re done. Just give up.”

He huffs out an angry, defiant breath through his nose and you sigh.

Of _course_ the little bitch wanted to play hardball.

“You think you’re fooling anyone?” you demand. “You think I don’t know how bad you _wanted_ this?”

Your pet squawks in outrage, but you’re done being sweet.

You shove him, rolling him over onto his side. It’s an awkward position, probably very uncomfortable with the way you’ve got all his limbs tied behind his back, but you don’t care. It gives you better access and you slip your fingers between his legs.

“What’s this, huh?” you wonder. He grunts as you press two digits against his slick folds, sliding inside him with ease. “You think anybody would have a cunt this wet if they _didn’t_ want to get fucked?”

You watch your pet squirm as you fuck him with your fingers. He just gets wetter and wetter and you make sure he can hear it, adding another finger just to listen to him whine.

“I bet you threw that whole little tussle,” you hum, stroking over his skull with your free hand. He doesn’t try to shake you off this time, and his cheekbones are starting to glow. “You couldn’t _wait_ for me to tie you up and use you like a whore. Is that it?”

He whines louder.

You double-down.

You splay the fingers you have inside his pussy, making him really _feel_ the stretch and he goes stiff, but you think you can do better.

He didn’t seem to appreciate your petting his skull. Maybe he’d like it more if you rubbed that plump little clit of his.

He squeaks—honest to god _squeaks_ when you do, and you laugh even as his humiliated blush glows brighter.

“Come on, cutie,” you chuckle. “You _want_ to be my little slut. There’s nothing you can do about it anyway. Just let go, already…”

You look deep into those pretty purple eye-lights of his. You see desperation in them, arousal, and maybe just a touch of fear…

…and behind them, you see something crack.

He sobs, clenching his eye-sockets shut. He throws his head back with a muffled moan and starts rocking down onto you.

Your pet is actively fucking himself on your fingers.

“Good boy…” You bend down, giving him a kiss over the bit. He huffs and strains forward when you pull away, like he didn’t want you to go. “ _Good_ boy… Do you want to come?”

He nods…but you think you want more.

“Ah-ah-ah—you have to _ask_ if you want to come.”

He just stares at you a moment, desperately confused. You have him gagged, but you want him to talk? He _can’t,_ he’d just make ridiculous, unintelligible noises!

You let a slow smirk spread across your face to show him that you know; that’s _exactly_ what you want.

He flushes harder, whining almost pitifully, but when you slow the thrusting of your fingers, he tries.

“‘EESH….‘EESH ‘ET ‘E ‘OME…”

Your grin feels almost as sharp as his.

“Well…alright, I guess you’ve been a good little slut for me. Come, then.”

You finger-fuck him faster, _deeper_ and the awkward jerking of his hips helps you along. You watch him start panting in earnest as he shuts his eye-sockets, chasing his orgasm with single-minded focus even bound and gagged here at your mercy.

When he finally catches it, he shudders so hard he _rattles,_ and you giggle a little to feel how tightly his pussy clenches around you, his slick squirting out of him and all over your hand.

“Good boy,” you murmur gently, letting him come down a little. “Good boy, Sans, that was beautiful…”

The sound of his name seems to wake him up a little. He blinks up at you, a little dazed like he always is after a scene this intense, needing a minute to pull himself back from subspace.

You know he’s back when a single blue bone shoots up from the floor, a very clear signal that you can understand even with his whole body in a hog-tie and a bit between his teeth.

‘STOP,’ we’re done.

You undo the bit first and hold onto it, even as you reach over him and one-handedly undo the knots binding his arms and legs. There was a trick to it that made it easy for you, as long as _you_ weren’t the one bound in them.

“Shit, baby, you almost chomped this thing in half,” you say, marveling at the cracked bit in your hands. “We’re gonna have to get a new one for next time…”

“NO,” Sans says quickly. He sounds a little winded as he rolls his neck and shoulders, working out the tension from that stressful position he was in. “KEEP IT. COULD MAKE IT INTERESTING FOR NEXT TIME IF I ACTUALLY _DO_ BITE MY WAY THROUGH.”

Sans was a mystery to you in some ways.

He loved being in charge, especially in the bedroom, and he’d dominate you every time if you let him, but if you fought him for control…

Apparently nothing else got his metaphorical blood pumping quite so much as _that._

He just loved the fight, said it was _thrilling_ trying to physically wrestle it from you—especially because you were both very willing participants in the rough and tumble game and would have fun no matter who came out victorious.

It was a hard fight for you to win, up against a trained officer in the Royal Guard. You were allowed to use anything you wanted to level the playing field and for after that, Sans had told you the kind of things he wanted you to do to him when you won, the kind of things he wanted you to say.

The times that you did win, the rewards were sweet for _both_ of you.

Even if you sometimes ended up with a nasty mark or two in the process, like the big honking bite-mark still slowly bleeding on your shoulder.

Sans’ clawed hand settles carefully over the wound even as you think of it, though, pouring powerful green magic into you. Your torn skin knits together easily, leaving not so much as a scratch behind, as if it had never even happened.

“SORRY, MY DEAR,” he murmurs apologetically. “I DIDN’T MEAN TO BE SO ROUGH WITH YOU.”

You chuckle. “Yes, you did.”

Sans smirks at you. “I DID,” he agrees. “I THINK YOU GOT ME BACK FOR IT, THOUGH, SO WHY DON’T WE CALL IT EVEN?”

You lean over and give him a kiss in agreement. He holds his razor-sharp teeth with infinite care against your lips now that the game is over and it makes you smile.

Sans is back to your loving, uptight workaholic boyfriend, and you’re back to his happy, affectionate datemate.

…Until the next time you play, of course.

You wonder who’ll win.

**Notes for the Chapter:**

> ......remember the first Kinktober chapter I did with SF!Sans where I was barely kinky at all and I said it was because I headcanon him as having some intense kinks and didn't want to just dive right in without testing him out in some fluff and character development first?
> 
> ...yeah, this is why. Not everybody from a Fell Universe can be a crunchy marshmallow like UF!Sans. SF!Sans is a very different sort of boy, but I still managed to work it around to a healthy, cuddly relationship by the end!
> 
> Thanks for reading, even if this chapter isn't your thing, and please please please take care of yourselves and your triggers! I tried to make the warnings on this obvious so nobody was caught by surprise. :)
> 
>  
> 
> [My tumblr!](https://popatochisssp.tumblr.com/)


	29. Soft (HT!Papyrus/Reader, Somnophilia)

**Notes for the Chapter:**

>  **Day 29:** ~~Glory hole~~ | ~~Double (Or more) Penetration~~ | _Sleepy Sex_ | ~~Massage~~
> 
>  **Pairing:** HT!Papyrus/Reader
> 
>  **Additional Kinks:** Gaping, creampie, consensual somnophilia

Oh goodness, he’s _nervous._

Contrary to popular opinion—and he’s made sure to _keep_ it a popular opinion—Papyrus is actually nervous quite a bit.

He’s had a lot of things in his life to be nervous _about,_ but he refuses to let it hold him back anymore.

He has a lot of things that calm him down, too, and with counseling he’s found it easier and easier lately to remind himself of them when his stress levels unexpectedly spike.

Papyrus is on the surface now, and in a few hours he’s going to get to see the sun rise for the twelve-hundred-and-sixteenth time. His brother made it out too and he’s snoring like a lazybones in his room down the hall, alive and safe. His garden is in bloom, colorful and bursting with vibrant greenery tended to life by his own two hands. 

And right now, right here, Papyrus has _you._

It’s late. Most people are wasting their time with sleeping—you included—but he won’t even entertain the thought with an enchanting little thing like you lying here next to him.

Your soft human body lain supine across his sheets, illuminated by moonlight through the window is one of the loveliest sights Papyrus has had the pleasure of experiencing. Your skin is flush with health and your chest is rising and falling with the steady rhythm of your breath and you are just completely, totally…

Amazing.

Stars _above,_ he doesn’t deserve you…

……No! Negativity! Unhelpful thought patterns!

Papyrus looks at you again.

No one _deserves_ anyone, he reminds himself. You’re a person with thoughts and emotions and opinions, and you’d made a decision to share your life with him. You _chose_ him because that was what you wanted and whether he understood it or not, it was a choice that made him very happy.

Papyrus had made the very same choice about you.

He reaches out, tracing his phalanges along the warm flesh of your thigh all the way down to your knee. He grasps it and…

………

 _Why_ is he still nervous?!

“You _Said_ It Was Okay,” Papyrus grumbles at your sleeping form in annoyance (though mostly at himself).

His tone was soft as if to keep from waking you, but you wouldn’t wake anytime soon.

Not after the way you had come to bed with him, made love with him, and then swallowed a sleeping pill before lying down for the night.

You were thoroughly _out_ and more importantly, _you’d said it was okay._

Papyrus spreads your legs. You’re still wide open and wet from where he’d pressed into you earlier and the sight makes his cock manifest almost unintentionally.

He can’t believe how accommodating your body can be for him, how much you can _take_ just because you trained yourself to; because you wanted to feel him inside you so _much._

Looking at you like this—unconscious, vulnerable, trusting, _open_ —Papyrus feels like the best mate in the world.

And he wants to prove it.

He’s careful with you as he settles between your legs, lining himself up with your well-used entrance. You probably don’t need it, but the last thing he wants to do is wake you with any sort of pain, so Papyrus makes sure his dick is positively dripping with magic to ease the way.

Sliding into your warm, unresisting body feels like a dream.

You take him with no trouble at all and don’t even stir beyond an instinctive arch of your hips and a breathy little sigh that falls almost daintily from your lovely human lips.

Papyrus _has_ to bend down to kiss them, even as he starts to ever so gently rock his hips against yours.

He never thought he’d get to actually do this.

He’d felt so _guilty_ when you cleverly cornered him and made him admit this secret fantasy of his and the…impure thoughts he’d had about you, watching you sleep in his bed night after night, looking soft and sweet and alluring beyond words.

He _never_ would’ve acted on it without your enthusiastic permission, but when he actually received it, he’d very nearly turned your offer down out of panic.

Papyrus shudders to imagine the reality where he never got to experience _this._

The warm clench of your walls around his cock, fluttering with each slow drag in and out, is heavenly beyond his wildest imagining and your slack and innocent expression makes his soul feel so full in his ribcage that he fears for one irrational moment it might actually _burst._

“I Love You,” he breathes heatedly against your lips, caressing every curve and dip of your body while you slumber on beneath him. “ _Stars_ , I Love You…”

The closest you get to waking is when Papyrus is too close to coming to keep from picking up his pace, fucking into you harder and deeper than before.

You moan a little and squirm, tightening around him, but he shushes you back to quiescence with soothing touches and quiet praises as he spills inside you.

You’re still deliciously pliant and sweet as Papyrus gathers you up in his arms afterward, cradling your sleeping body against his chest.

His come is dripping out of you and he really should clean you off, but at the same time… he wants you to _feel_ it when you eventually wake up.

Papyrus wants to _watch_ you sit up, all groggy and adorably disoriented the way you always are in the morning and feel the ache between your legs, the sticky come he’d left inside you because he was your mate and he could do that; he could make love to you _so_ gently and carefully that you stayed asleep through the whole thing.

He strokes your hair and you shift a little against his ribs, trying to nuzzle your way closer to him.

Papyrus melts and cuddles you with all the affection he has in his battered bones.

He hopes you wake before sunrise. He’d love nothing more than to watch Number Twelve-Hundred-And-Sixteen with you.

**Notes for the Chapter:**

> Is the actual prompt technically 'sleepy sex'? Yes. Did I write 'full-on somnophilia' instead? Also yes.
> 
> Was this intentional? Triple yes, I liked the idea better, so I ran with it. It's my Kinktober, I'll kink how I wanna! XD
> 
>  
> 
> [My tumblr!](https://popatochisssp.tumblr.com)


	30. Patient (US!Papyrus/Reader, Stockings/Tights/Pantyhose)

**Notes for the Chapter:**

>  **Day 30:** ~~Gagging~~ | _Stockings/Tights/Pantyhose_ | ~~Breast Worship~~ | ~~Swallowing~~
> 
>  **Pairing:** US!Papyrus/Reader
> 
>  **Additional Kinks:** Lingerie, slight foot fetish, (bone kink?)

Papyrus was a pretty patient guy.

It was something he prided himself on, especially since it was such an easy thing for him to be. Just sit and wait? Not a problem.

Hang out all night outside Undyne’s house because she forgot he was coming over and got super-invested in her weird cartoons? Sure, he loved outdoor napping.

Wait for Sans to finish monologuing his way into the Royal Guard by talking Alphys half to death? Yeah, he was used to hearing long lectures out of his bro and he wasn’t even on the receiving end of this one, no skin off his nose—he didn’t have either of those things, anyway.

Trying to be cool and wait for you to come out of your room, though…?

If Papyrus _had_ any skin, he’d be crawling out of it by now.

“babe? you good?”

There was a pause before your muffled voice drifted through the door.

“…I dunno, Papyrus, it’s… I dunno…”

“what don’t you know?” he asked. “do they not fit?”

Another pause.

“No, they…they fit, I just… I feel kinda silly… I’m not even sure it’s all on right. What if it looks weird?”

“i can check for you,” Papyrus suggested a little eagerly. It seemed like an ideal solution to him and he took a step closer, reaching for the doorknob.

“Mmm…maybe I should just take them off.”

_oh, **hell** no._

Forget the knob. Forget the entire door.

Papyrus stepped forward into your room and finally, _finally_ got a good look at you.

“oh _wow_ …”

You jumped when you saw him, turning away from the mirror as your cheeks heated in embarrassment.

“Papyrus! I locked that for a reason!”

He was deaf to your attempt at a scolding. All he could hear was the thrumming of his own soul in his bones and all he could see was _you._

You looked _fantastic_ in the cute little lingerie set he picked out for you.

The lacy, frilly fabric—integrity-blue with a sheen of perseverance-purple—barely concealed anything, hugging your body in a way that was positively obscene. You looked like the sexiest present in the world, wrapped up all ready for him to enjoy. Even as you shifted awkwardly, self-consciously in front of him, he felt his tongue manifesting in his jaw just so he could drool over how smoking hot you looked.

Papyrus watched you nervously fidget with the garter belt, but it only drew his eye-socket to your hips and then your thighs, where the belt clipped onto those sheer stockings pulled up over your legs and…

Okay, yeah. He was done with patience.

You squeaked a little as he dropped to his knees and caught you by the thigh, leaning forward to nuzzle you through the thin, sheer fabric.

“Papyrus…!?”

“mmm, you’re so fuckin’ sexy, babe…worryin’ over nothin’…”

“I…” You looked down at him as he caressed your legs through the nylon stockings like a man possessed. “…Do I really look okay?”

“‘okay’?” Papyrus stood and scooped you up, popping you over onto your bed before putting his hands right back on your sexy calves. “you look _great._ ”

You leaned back on your elbows as he took your leg and lifted it up, pressing his teeth to your ankle.

Papyrus could feel the warmth of your skin through the stocking, but down here he could feel your bones, too. He thought that was the _coolest_ damn thing, that under all your soft human flesh you were built almost the exact same way he was.

It was also unbearably _hot_ and Papyrus gives you another heated nuzzle right where your talus and your tibia and fibula all meet.

You seem to be getting some of your confidence back because a smirk works its way across your face.

“Are you gonna make this weird?” you teasingly wonder. “Like you made the foot-rub weird?”

Papyrus chuckles. “is it really ‘weird’ if it ends in mutual orgasms?”

“Hm. Touché.” You pull your leg back and plant your cute little indigo toes right on his sternum. “I still think maybe you’re just freaky…”

Papyrus raises a browbone at you, even as your foot drags further down, poking at his xyphoid process and making him shiver.

“yeah? an’ what’s that make you?” he challenges.

“The human that’s dating ‘freaky,’” you grin. You drop your leg even further and settle your sole along the curve of his ilium. “And the human that wants you to peel all this nylon and lace off with your teeth.”

Papyrus’ magic flares in his chest and his pelvis and he grins right back at you.

“ _double_ -freaky, then. i can roll with that…”

Your laughter is music to his non-existent ears… but so is your moaning and Papyrus is ready to do whatever it takes to have his own private symphony with you tonight.

Thank the _stars_ he was a patient guy.

…Most of the time.

**Notes for the Chapter:**

> "Is US!Papyrus the kinkiest of your skeletons?"
> 
> Me, Intellectually: Well, I guess it's not really fair to say _that,_ kink is such a broad spectrum and there's scales of things. What's kinky and maybe even popularly considered 'unusual' is entirely subjective from person to person and some of my other skeles are _way_ out there on that scale, it's not an easy thing to quantify...
> 
> Me, Emotionally: Yes, he is my grossest, weirdest boy, he wants to buy you pretty stockings and touch your feet while you wear them and feel up all your bones and then have you call him 'daddy,' he's a very kinky, nasty boy.
> 
> Me, Out Loud: ......Yeah, a little bit.


	31. Sinking (???/Reader, Mind Control)

**Notes for the Chapter:**

>  **Day 31:** ~~Any combination of the above!~~ | _Mind Control/Brainwashing/Hypnosis_
> 
>  **Pairing:** ???/Reader
> 
>  **Additional Kinks:** Dub-con (consensual temporary brainwashing, but no way to back out mid-act if that's a squick to anyone), possessiveness, obedience, identity loss

“ _Relax._ ”

He was trying. It wasn’t as easy as it sounded.

“You’re fighting me, baby. I need you to relax if this is gonna work.”

He _knows._ He can’t help it, it’s instinctive. It’s a reflex, he can’t just _stop._

You sigh, taking hold of his skull.

“Look at me,” you tell him.

He does.

Your eyes are the first thing he sees and suddenly, all he can think of is how incredibly beautiful they are.

Their glow is so enticing in the darkness of the room… He never wants to look away again.

His consciousness blurs and he feels…strange. Weightless, like he’s floating…or maybe sinking…?

That feels more right. He’s sinking, deeper and deeper down, like into a vast ocean. His limbs feel…strangely heavy, he…

He can’t fight this.

Soon, he’s not sure why he’d have wanted to.

His bones are so warm, even as he sinks down into this comfortable abyss and he feels…

Safe. Loved. _Owned._

When you push him down, laying him flat on his back, he doesn’t protest. He doesn’t say a word as you start taking off his clothes, either, leaving him totally bare before you.

He is yours to do with as you choose. He knows that now.

“Good boy,” you say softly, and the praise from your lips makes him shiver with pleasure. He wants you to praise him more. He wants to please you, more than anything in the world.

He still hears the whispered commands you embedded in his soul.

_Relax. Submit. Obey._

He will. He’s _yours._

You bend over him, cupping his face and stroking your thumbs along his cheekbones. Your touch feels like a benediction and he presses into your hands, desperate to feel you even more.

“Hey there, precious,” you greet him, and he smiles, dazed and delighted at the pretty glowing eyes you fix on his. “Can you tell me your name?”

……His…his name…?

Did he have one?

Was it important?

He frowns. “I don’t know,” he says out loud. “I’m sorry…”

…Something about his words feels weird.

What case is he speaking in? Lower? Upper? Proper?

You chuckle and his skull goes empty again.

“Don’t be sorry, sweetheart, that’s perfect. A nice blank slate until I wake you up…”

Oh. That’s right: he’s _yours._ He’s speaking _your_ case.

He sighs happily as your hands drift down lower, your warm, wonderful fingers petting along his clavicle, skimming down his sternum, dancing along his ribs.

The barest touch from you sends pure pleasure thrumming through his soul and he can’t get enough of it.

“Make a dick for me, baby.”

He does it immediately, his magic coalescing into the shape you asked for without hesitation.

He’s not sure he _could_ refuse you right now…but why would he ever want to?

“Here’s what’s going to happen,” you say. Your smile is _dazzlingly_ beautiful and he can’t look away. “I’m going to touch you.”

_Yes._

“I’m going to fuck you.”

_**Yes.** _

“I’m going to make you come for me, over and over again.”

_Stars, please, **yes** …!_

“And when you can’t come anymore, not even one little drop, _then_ I’ll let you wake up. Okay?”

His soul is still murmuring the truths you gave him.

_Relax. Submit. Obey._

He knows his answer.

“Anything you want…”

You’re stunning when you grin that way. The luminous magic in your eyes makes him think you must be the most striking mage in the world.

“Good boy,” you purr at him, so sweet and affectionate. “Let’s get started, shall we?”

He can’t believe how lucky he is.

He gets to belong to _you._

**Notes for the Chapter:**

> Which skeleton do you have mind-wiped at your beck and call...? Your choice, whichever skeleton is your favorite. ;D
> 
> Posting this a little early because I can't wait for Halloween to do it, I'm too impatient, but also I just couldn't wait to give an exuberant thank you to everybody who's been reading/commenting/kudos'ing this fic! You're all the absolute best and I love every one of you! :D
> 
> I started this Kinktober fic on a total whim, just wanting to test out some headcanons and characterization for some Undertale AU skeletons and I got so much more of a response than I was expecting, much less one so positive! 
> 
> I'll probably tack one more chapter onto this thing, a table of contents sort of deal to make it easy to find the chapters with your favorite skeleton in it, but we're just about done here. While this may be the end of this particular fic, though, I'm definitely not done with the Undertale fandom!
> 
> My Horrortale fic, [Fur a Good Time, Call...](https://archiveofourown.org/works/15881328/chapters/37005171) is next on my project list, but I've got some ideas for other fics and a stupidly long list of headcanons for all these skeletons, so there's bound to be more where...whatever all of this is...came from! XD
> 
> Thanks again and Happy Halloween/Kinktober! And naturally, come stop by [my tumblr](https://popatochisssp.tumblr.com/) if you want to talk! ;D


	32. Quick Links (Table of Contents)

**Summary for the Chapter:**

> For convenience, this is just a fast way to navigate the 31 chapters of this fic, especially if you're looking for a specific skeleton!
> 
> No new fic-content here.

**Undertale Sans**

  * [Subject (Medical Play)](https://archiveofourown.org/works/16230119/chapters/37942184)
  * [Lazy (Hot-Dogging)  
](https://archiveofourown.org/works/16230119/chapters/38312852)
  * [Challenge Accepted (Toys)](https://archiveofourown.org/works/16230119/chapters/38505659)



**Undertale Papyrus**

  * [Beautiful (Mirror Sex)](https://archiveofourown.org/works/16230119/chapters/38090846)
  * [Experiment (Body Swap)](https://archiveofourown.org/works/16230119/chapters/38121350)
  * [Stamina (Fucking Machine)](https://archiveofourown.org/works/16230119/chapters/38303720)



**Underswap Sans**

  * [Napoleon (Bondage)](https://archiveofourown.org/works/16230119/chapters/38134880)
  * [Satisfaction (Cunnilingus)](https://archiveofourown.org/works/16230119/chapters/38268173)
  * [Safe (Against a Wall)](https://archiveofourown.org/works/16230119/chapters/38509892)



**Underswap Papyrus**

  * [Needy (Daddy Kink)](https://archiveofourown.org/works/16230119/chapters/38101022)
  * [Stress Relief (Handjobs)](https://archiveofourown.org/works/16230119/chapters/38464061)
  * [Patient (Stockings/Tights/Pantyhose)](https://archiveofourown.org/works/16230119/chapters/38552435)



**Underfell Sans**

  * [Trust (Sensory Deprivation)](https://archiveofourown.org/works/16230119/chapters/38087288)
  * [Open (Bonds [Telepathic or Empathic])](https://archiveofourown.org/works/16230119/chapters/38211665)
  * [Lucky (Body Worship)](https://archiveofourown.org/works/16230119/chapters/38278049)



**Underfell Papyrus**

  * [Perfect (Deep-Throating)](https://archiveofourown.org/works/16230119/chapters/37939280)
  * [Hero (Costume)](https://archiveofourown.org/works/16230119/chapters/38235614)
  * [Revenge (Public)](https://archiveofourown.org/works/16230119/chapters/38309897)



**Swapfell Sans**

  * [Surprise (Collaring)](https://archiveofourown.org/works/16230119/chapters/38286176)
  * [Heel (Boot Worship)](https://archiveofourown.org/works/16230119/chapters/38499152)
  * [Game (Humiliation)](https://archiveofourown.org/works/16230119/chapters/38514023)



**Swapfell Papyrus**

  * [New Things (Sounding)](https://archiveofourown.org/works/16230119/chapters/38232461)
  * [Delicious (Food Play)](https://archiveofourown.org/works/16230119/chapters/38316233)
  * [Great Taste (Pegging)](https://archiveofourown.org/works/16230119/chapters/38473436)



**Horrortale Sans**

  * [Sugar (Feederism)](https://archiveofourown.org/works/16230119/chapters/38093702)
  * [Family Way (Creampie)](https://archiveofourown.org/works/16230119/chapters/38249120)
  * [Big (Size Difference)](https://archiveofourown.org/works/16230119/chapters/38469113)



**Horrortale Papyrus**

  * [Full Up (Fisting)](https://archiveofourown.org/works/16230119/chapters/38132468)
  * [Messy (Intercrural Sex)](https://archiveofourown.org/works/16230119/chapters/38273285)
  * [Soft (Somnophilia)](https://archiveofourown.org/works/16230119/chapters/38532623)



**??? (Insert Your Favorite Skeleton Here)**

  * [Sinking (Mind Control)](https://archiveofourown.org/works/16230119/chapters/38556980)



**Notes for the Chapter:**

> Hopefully this'll be good for navigating, let me know if this needs anything to make it more convenient! :)


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